Q&A Hero

Q: A researcher believes a new diet should improve weight gain. To test his hypothesis a random sample of 10 people on the old diet and an independent random sample of 10 people on the new diet were selected. The selected people on the old diet gain an average of 5 pounds with a standard deviation of 2 pounds, while the average gain for selected people on the new diet was 8 pounds with a standard deviation of 1.5 pounds. Assume that the values are normally distributed in each population and that the population variances are approximately equal. Using a= 0.05, the critical tvalue used from the table for this is _______. a) -1.96 b) -1.645 c) -2.100 d) -3.79 e) -1.734

Q: A researcher wishes to determine the difference in two population means. To do this, she randomly samples 9 items from each population and computes a 90% confidence interval. The sample from the first population produces a mean of 780 with a standard deviation of 240. The sample from the second population produces a mean of 890 with a standard deviation of 280. Assume that the values are normally distributed in each population and that the population variances are approximately equal. The critical tvalue used from the table for this is _______. a) 1.860 b) 1.734 c) 1.746 d) 1.337 e) 2.342

Q: A researcher wishes to determine the difference in two population means. To do this, she randomly samples 9 items from each population and computes a 90% confidence interval. The sample from the first population produces a mean of 780 with a standard deviation of 240. The sample from the second population produces a mean of 890 with a standard deviation of 280. Assume that the values are normally distributed in each population. The point estimate for the difference in the means of these two populations is _______. a) -110 b) 40 c) -40 d) 0 e) 240

Q: A researcher is interested in testing to determine if the mean price of a casual lunch is different in the city than it is in the suburbs. The null hypothesis is that there is no difference in the population means (i.e. the difference is zero). The alternative hypothesis is that there is a difference (i.e. the difference is not equal to zero). He randomly selects a sample of 9 lunch tickets from the city population resulting in a mean of $14.30 and a standard deviation of $3.40. He randomly selects a sample of 14 lunch tickets from the suburban population resulting in a mean of $11.80 and a standard deviation $2.90. He is using an alpha value of .10 to conduct this test. Assuming that the populations are normally distributed, the critical tvalue from the table is _______.a) 1.323b) 1.721c) 1.717d) 1.321e) 2.321

Q: A researcher is interested in testing to determine if the mean price of a casual lunch is different in the city than it is in the suburbs. The null hypothesis is that there is no difference in the population means (i.e. the difference is zero). The alternative hypothesis is that there is a difference (i.e. the difference is not equal to zero). He randomly selects a sample of 9 lunch tickets from the city population resulting in a mean of $14.30 and a standard deviation of $3.40. He randomly selects a sample of 14 lunch tickets from the suburban population resulting in a mean of $11.80 and a standard deviation $2.90. He is using an alpha value of .10 to conduct this test. Assuming that the populations are normally distributed and that the population variances are approximately equal, the degrees of freedom for this problem are _______. a) 23 b) 22 c) 21 d) 2 d) 1

Q: A researcher wants to estimate the difference in the means of two populations. A random sample of 36 items from the first population results in a sample mean of 430. A random sample of 49 items from the second population results in a sample mean of 460. The population standard deviations are 120 for the first population and 140 for the second population. From this information, a 95% confidence interval for the difference in population means is _______. a) -95.90 to 35.90 b) -85.44, 25.44 c) -76.53 to 16.53 d) -102.83 to 42.43 e) 98.45 to 125.48

Q: Lucy Baker is analyzing demographic characteristics of two television programs, American Idol(population 1) and 60 Minutes (population 2). Previous studies indicate no difference in the ages of the two audiences. (The mean age of each audience is the same.) Her staff randomly selected 100 people from each audience, and reported the following: 1= 43 years and 2= 45 years. Assume that 1= 5 and 2= 8. With a two-tail test and a= .05, the appropriate decision is _________________.a) do not reject the null hypothesis 1- 2= 0b) reject the null hypothesis 1- 2>0c) reject the null hypothesis 1- 2= 0d) do not reject the null hypothesis 1- 2<0e) do nothing

Q: Lucy Baker is analyzing demographic characteristics of two television programs, American Idol(population 1) and 60 Minutes (population 2). Previous studies indicate no difference in the ages of the two audiences. (The mean age of each audience is the same.) Her staff randomly selected 100 people from each audience, and reported the following: 1= 43 years and 2= 45 years. Assume that 1= 5 and 2= 8. Assuming a two-tail test and a= .05, the observed zvalue is _________________.a) -2.12b) -2.25c) -5.58d) -15.38e) -20.68

Q: Lucy Baker is analyzing demographic characteristics of two television programs, American Idol(population 1) and 60 Minutes (population 2). Previous studies indicate no difference in the ages of the two audiences. (The mean age of each audience is the same.) Her staff randomly selected 100 people from each audience, and reported the following: 1= 43 years and 2= 45 years. Assume that 1= 5 and 2= 8. With a two-tail test and a= .05, the critical zvalues are _________________.a) -1.64 and 1.64b) -1.96 and 1.96c) -2.33 and 2.33d) -2.58 and 2.58e) -2.97 and 2.97

Q: Lucy Baker is analyzing demographic characteristics of two television programs, American Idol(population 1) and 60 Minutes (population 2). Previous studies indicate no difference in the ages of the two audiences. (The mean age of each audience is the same.) Lucy plans to test this hypothesis using a random sample of 100 from each audience. Her alternate hypothesis is ____________. a) 1- 2<0 b) 1- 2>0 c) 1- 2= 0 d) 1- 2 0 e) 1- 2= 1

Q: Lucy Baker is analyzing demographic characteristics of two television programs, American Idol(population 1) and 60 Minutes (population 2). Previous studies indicate no difference in the ages of the two audiences. (The mean age of each audience is the same.) Lucy plans to test this hypothesis using a random sample of 100 from each audience. Her null hypothesis is ____________. a) 1- 2 0 b) 1- 2>0 c) 1- 2= 0 d) 1- 2<0 e) 1- 2<1

Q: Golf course designer Roberto Langabeer is evaluating two sites, Palmetto Dunes and Ocean Greens, for his next golf course. He wants to prove that Palmetto Dunes residents (population 1) play golf more often than Ocean Greens residents (population 2). Roberto commissions a market survey to test this hypothesis. The market researcher used a random sample of individuals from each suburb, and reported the following: 1= 16 times per month and 2= 14 times per month. Assume that 1= 4 and 2= 3. With a= .01, the appropriate decision is _____________.a) do nothingb) reject the null hypothesis s1< s2c) accept the alternate hypothesis 1- m2> 0d) reject the alternate hypothesis n1= n2= 64e) do not reject the null hypothesis 1- 2= 0

Q: Golf course designer Roberto Langabeer is evaluating two sites, Palmetto Dunes and Ocean Greens, for his next golf course. He wants to prove that Palmetto Dunes residents (population 1) play golf more often than Ocean Greens residents (population 2). Roberto commissions a market survey to test this hypothesis. The market researcher used a random sample of 64 individuals from each suburb, and reported the following: 1= 16 times per month and 2= 14 times per month. Assume that 1= 4 and 2= 3. With a= .01, the observed zvalue is _________________.a) 18.29b) 6.05c) 5.12d) 3.40e) 3.20

Q: Golf course designer Roberto Langabeer is evaluating two sites, Palmetto Dunes and Ocean Greens, for his next golf course. He wants to prove that Palmetto Dunes residents (population 1) play golf more often than Ocean Greens residents (population 2). Roberto commissions a market survey to test this hypothesis. The market researcher used a random sample of 64 individuals from each suburb, and reported the following: 1= 15 times per month and 2= 14 times per month. Assume that 1= 2 and 2= 3. With a= .01, the appropriate decision is _________________.a) reject the null hypothesis 12< 22b) accept the alternate hypothesis 1- m2> 0c) reject the alternate hypothesis n1= n2= 64d) fail to reject the null hypothesis 1- 2= 0e) do nothing

Q: Golf course designer Roberto Langabeer is evaluating two sites, Palmetto Dunes and Ocean Greens, for his next golf course. He wants to prove that Palmetto Dunes residents (population 1) play golf more often than Ocean Greens residents (population 2). Roberto commissions a market survey to test this hypothesis. The market researcher used a random sample of 64 individuals from each suburb, and reported the following: 1= 15 times per month and 2= 14 times per month. Assume that 1= 2 and 2= 3. With a= .01, the observed zvalue is _________________.a) 2.22b) 12.81c) 4.92d) 3.58e) 1.96

Q: Golf course designer Roberto Langabeer is evaluating two sites, Palmetto Dunes and Ocean Greens, for his next golf course. He wants to prove that Palmetto Dunes residents (population 1) play golf more often than Ocean Greens residents (population 2). Roberto commissions a market survey to test this hypothesis. The market researcher used a random sample of 64 individuals from each suburb, and reported the following: 1= 15 times per month and 2= 14 times per month. Assume that 1= 2 and 2= 3. With a= .01, the critical zvalue is _________________.a) -1.96b) 1.96c) -2.33d) -1.33e) 2.33

Q: Golf course designer Roberto Langabeer is evaluating two sites, Palmetto Dunes and Ocean Greens, for his next golf course. He wants to prove that Palmetto Dunes residents (population 1) play golf more often than Ocean Greens residents (population 2). Roberto plans to test this hypothesis using a random sample of 81 individuals from each suburb. His null hypothesis is __________.His alternative hypothesis is __________.

Q: Golf course designer Roberto Langabeer is evaluating two sites, Palmetto Dunes and Ocean Greens, for his next golf course. He wants to prove that Palmetto Dunes residents (population 1) play golf more often than Ocean Greens residents (population 2). Roberto plans to test this hypothesis using a random sample of 81 individuals from each suburb. His null hypothesis is __________.

Q: The ratio of two independent sample variances follows the F distribution.

Q: The Fstatistic is a ratio of two independent sample variances.

Q: The Ftest of two population variances is extremely robust to the violations of the assumption that the populations are normally distributed.

Q: A coffee-dispensing machine is supposed to deliver 8 ounces of liquid into each paper cup, but a consumer believes that the actual mean amount is less. The consumer obtained a sample of 49 cups of the dispensed liquid with average of 7.75 ounces. If the sample variance of the dispensed liquid per cup is 0.81 ounces, and α=0.05, the p-value is approximatelya) 0.05b) 0.025c) 0.06d) 0.015e) 0.10

Q: A recent survey suggests 30% of boat owners do not regularly use their boat after the second year of ownership. A local boat dealer wants to test the alternative hypothesis that p ≠.30with α = .05. He surveys 60 boat owners and finds 42% of the owners who have owned their boat for three years report they do not regularly use their boat. Assuming that p = .35, the probability of type II error is approximatelya) 0.8542b) 0.1458c) 0.3577d) 0.1423e) 0.4965

Q: A laptop battery lifespan follows a normal distribution with mean μ = 22 months and a standard deviation s=6 months. To test the alternative hypothesis that μ < 22 with α = .01, 36 laptop batteries are randomly selected. Assuming that μ=24, the probability of type II error is approximatelya. -.01b. 2.33c. -4.33d. 0.01e. 0.00

Q: A laptop battery lifespan follows a normal distribution with mean μ = 22 months and a standard deviation s=6 months. To test the alternative hypothesis that μ < 22with α = .05, 36laptop batteries are randomly selected. Assuming that μ=21, the probability of type II error is approximatelya. -0.65b. 0.2422c. 0.64d. 0.7422e. 0.2508

Q: The lifetime of a squirrel follows a normal distribution with mean μ= 40 months and a standard deviation s=7 months. To test the hypothesis that μ>40, 25 squirrels are randomly selected. Assuming that μ=45, and α=0.1, the probability of type II error is approximatelya) 0.076b) 0.016c) 0.05d) 0.011e) 0.983

Q: The lifetime of a squirrel follows a normal distribution with mean μ months and a standard deviation s=7 months. To test the alternative hypothesis that μ > 40, 25 squirrels are randomly selected. The null hypothesis is rejected when the sample mean is bigger than 43. Assuming that μ=45, the probability of type II error is approximatelya) 0.076b) 0.016c) 0.05d) 0.011e) 0.983

Q: David Desreumaux, VP of Human Resources of American First Banks (AFB), is reviewing the employee training programs of AFB banks. Based on a recent census of personnel, David knows that the variance of teller training time in the Southeast region is 8, and he wonders if the variance in the Southwest region is the same number. His staff randomly selected personnel files for 15 tellers in the Southwest Region, and determined that their mean training time was 25 hours and that the standard deviation was 4 hours. Assume that teller training time is normally distributed. Using = 0.10, the appropriate decision is ________. a) increase the sample size b) reduce the sample size c) fail to reject the null hypothesis d) maintain status quo e) reject the null hypothesis

Q: David Desreumaux, VP of Human Resources of American First Banks (AFB), is reviewing the employee training programs of AFB banks. Based on a recent census of personnel, David knows that the variance of teller training time in the Southeast region is 8, and he wonders if the variance in the Southwest region is the same number. His staff randomly selected personnel files for 15 tellers in the Southwest Region, and determined that their mean training time was 25 hours and that the standard deviation was 4 hours. Assume that teller training time is normally distributed. Using = 0.10, the observed value of chi-square is ________. a) 28.00 b) 30.00 c) 56.00 d) 60.00 e) 65.00

Q: David Desreumaux, VP of Human Resources of American First Banks (AFB), is reviewing the employee training programs of AFB banks. Based on a recent census of personnel, David knows that the variance of teller training time in the Southeast region is 8, and he wonders if the variance in the Southwest region is the same number. His staff randomly selected personnel files for 15 tellers in the Southwest Region, and determined that their mean training time was 25 hours and that the standard deviation was 4 hours. Assume that teller training time is normally distributed. Using = 0.10, the critical values of chi-square are ________. a) 7.96 and 26.30 b) 6.57 and 23.68 c) -1.96 and 1.96 d) -1.645 and 1.645 e) -6.57 and 23.68

Q: David Desreumaux, VP of Human Resources of American First Banks (AFB), is reviewing the employee training programs of AFB banks. Based on a recent census of personnel, David knows that the variance of teller training time in the Southeast region is 8, and he wonders if the variance in the Southwest region is the same number. His staff randomly selected personnel files for 15 tellers in the Southwest Region, and determined that their mean training time was 25 hours and that the standard deviation was 4 hours. Assume that teller training time is normally distributed. Using = 0.10, the null hypothesis is ________.a) = 25b) = 8c) = 4d) =< 8e) s2= 16

Q: Discrete Components, Inc. manufactures a line of electrical resistors. Presently, the carbon composition line is producing 100 ohm resistors. The population variance of these resistors "must not exceed 4" to conform to industry standards. Periodically, the quality control inspectors check for conformity by randomly select 10 resistors from the line, and calculating the sample variance. The last sample had a variance of 4.36. Assume that the population is normally distributed. Using = 0.05, the appropriate decision is _________________. a) increase the sample size b) reduce the sample size c) reject the null hypothesis d) fail to reject the null hypothesis e) maintain status quo

Q: Discrete Components, Inc. manufactures a line of electrical resistors. Presently, the carbon composition line is producing 100 ohm resistors. The population variance of these resistors "must not exceed 4" to conform to industry standards. Periodically, the quality control inspectors check for conformity by randomly select 10 resistors from the line, and calculating the sample variance. The last sample had a variance of 4.36. Assume that the population is normally distributed. Using = 0.05, the observed value of chi-square is _________________. a) 1.74 b) 1.94 c) 10.90 d) 9.81 e) 8.91

Q: Discrete Components, Inc. manufactures a line of electrical resistors. Presently, the carbon composition line is producing 100 ohm resistors. The population variance of these resistors "must not exceed 4" to conform to industry standards. Periodically, the quality control inspectors check for conformity by randomly select 10 resistors from the line, and calculating the sample variance. The last sample had a variance of 4.36. Assume that the population is normally distributed. Using = 0.05, the critical value of chi-square is _________________. a) 18.31 b) 16.92 c) 3.94 d) 3.33 e) 19.82

Q: Discrete Components, Inc. manufactures a line of electrical resistors. Presently, the carbon composition line is producing 100 ohm resistors. The population variance of these resistors "must not exceed 4" to conform to industry standards. Periodically, the quality control inspectors check for conformity by randomly selecting 10 resistors from the line, and calculating the sample variance. The last sample had a variance of 4.36. Assume that the population is normally distributed. Using = 0.05, the null hypothesis is _________________. a) = 100 b) 10 c) s2 4 d) 2= 4 e) n= 100

Q: Elwin Osbourne, CIO at GFS, Inc., suspects that at least 25% of e-mail messages sent by GFS employees are not business related. A random sample of 300 e-mail messages was selected to test this hypothesis at the 0.01 level of significance. Sixty of the messages were not business related. The appropriate decision is _______. a) increase the sample size b) gather more data c) maintain status quo d) fail to reject the null hypothesis e) reject the null hypothesis

Q: Elwin Osbourne, CIO at GFS, Inc., suspects that at least 25% of e-mail messages sent by GFS employees are not business related. A random sample of 300 e-mail messages was selected to test this hypothesis at the 0.01 level of significance. Fifty-four of the messages were not business related. The appropriate decision is _______. a) increase the sample size b) gather more data c) reject the null hypothesis d) fail to reject the null hypothesis e) maintain status quo

Q: Elwin Osbourne, CIO at GFS, Inc., suspects that at least 25% of e-mail messages sent by GFS employees are not business related. A random sample of 300 e-mail messages was selected to test this hypothesis at the 0.01 level of significance. Fifty-four of the messages were not business related. The null hypothesis is ____. a) b= 30 b) n= 300 c) p< 0.25 d) p≠0.25 e) p= 0.25

Q: The executives of CareFree Insurance, Inc. feel that "a majority of our employees perceive a participatory management style at CareFree." A random sample of 200 CareFree employees is selected to test this hypothesis at the 0.05 level of significance. Ninety employees rate the management as participatory. The appropriate decision is __________. a) fail to reject the null hypothesis b) reject the null hypothesis c) reduce the sample size d) increase the sample size e) maintain status quo

Q: The executives of CareFree Insurance, Inc. feel that "a majority of our employees perceive a participatory management style at CareFree." A random sample of 200 CareFree employees is selected to test this hypothesis at the 0.05 level of significance. Eighty employees rate the management as participatory. The appropriate decision is __________. a) fail to reject the null hypothesis b) reject the null hypothesis c) reduce the sample size d) increase the sample size e) do nothing

Q: The executives of CareFree Insurance, Inc. feel that "a majority of our employees perceive a participatory management style at CareFree." A random sample of 200 CareFree employees is selected to test this hypothesis at the 0.05 level of significance. Eighty employees rate the management as participatory. The null hypothesis is __________. a) n= 30 b) n= 200 c) p= 0.50 d) p< 0.50 e) n> 200

Q: Ophelia O'Brien, VP of Consumer Credit of American First Banks (AFB), monitors the default rate on personal loans at the AFB member banks. One of her standards is "no more than 5% of personal loans should be in default." On each Friday, the default rate is calculated for a sample of 500 personal loans. Last Friday's sample contained 38 defaulted loans. Using = 0.10, the appropriate decision is _______. a) reduce the sample size b) increase the sample size c) reject the null hypothesis d) fail to reject the null hypothesis e) do nothing

Q: Ophelia O'Brien, VP of Consumer Credit of American First Banks (AFB), monitors the default rate on personal loans at the AFB member banks. One of her standards is "no more than 5% of personal loans should be in default." On each Friday, the default rate is calculated for a sample of 500 personal loans. Last Friday's sample contained 30 defaulted loans. Using = 0.10, the appropriate decision is _______. a) reduce the sample size b) increase the sample size c) reject the null hypothesis d) fail to reject the null hypothesis e) do nothing

Q: Ophelia O'Brien, VP of Consumer Credit of American First Banks (AFB), monitors the default rate on personal loans at the AFB member banks. One of her standards is "no more than 5% of personal loans should be in default." On each Friday, the default rate is calculated for a sample of 500 personal loans. Last Friday's sample contained 30 defaulted loans. Using = 0.10, the observed zvalue is _______. a) 1.03 b) -1.03 c) 0.046 d) -0.046 e) 1.33

Q: Ophelia O'Brien, VP of Consumer Credit of American First Banks (AFB), monitors the default rate on personal loans at the AFB member banks. One of her standards is "no more than 5% of personal loans should be in default." On each Friday, the default rate is calculated for a sample of 500 personal loans. Last Friday's sample contained 30 defaulted loans. Using = 0.10, the critical zvalue is _______. a) 1.645 b) -1.645 c) 1.28 d) -1.28 e) 2.28

Q: Ophelia O'Brien, VP of Consumer Credit of American First Banks (AFB), monitors the default rate on personal loans at the AFB member banks. One of her standards is "no more than 5% of personal loans should be in default." On each Friday, the default rate is calculated for a sample of 500 personal loans. Last Friday's sample contained 30 defaulted loans. Ophelia's null hypothesis is _______. a) p> 0.05 b) p= 0.05 c) n= 30 d) n= 500 e) n= 0.05

Q: A small restaurant owner believes exactly 36 % of his customers come to the restaurant because of his daily half-price specials. He is interested in expanding his daily specials and increasing the price. However, he would like to test his hypothesis prior to expanding the daily special offerings. He intends to use the following null and alternative hypotheses. Ho: p= 0.36 Ha: p 0.36 These hypotheses _______________. a) indicate a one-tailed test with a rejection area in the right tail b) indicate a one-tailed test with a rejection area in the left tail c) indicate a two-tailed test d) are established incorrectly e) are not mutually exclusive

Q: A small restaurant owner believes at least 36 % of his customers would be willing to order take out service if it were available. He is interested in surveying his customer base. He intends to use the following null and alternative hypotheses. Ho: p 0.36 Ha: p< 0.36 These hypotheses _______________. a) indicate a one-tailed test with a rejection area in the right tail b) indicate a one-tailed test with a rejection area in the left tail c) indicate a two-tailed test d) are established incorrectly e) are not mutually exclusive

Q: A small restaurant owner believes no more than 36 % of his customers travel over 10 miles to his business. He is interested in expanding his customer base through marketing. However, he would like to test his hypothesis prior to investing money in a marketing initiative. He intends to use the following null and alternative hypotheses. Ho: p 0.36 Ha: p> 0.36 These hypotheses _______________. a) indicate a one-tailed test with a rejection area in the right tail b) indicate a one-tailed test with a rejection area in the left tail c) indicate a two-tailed test d) are established incorrectly e) are not mutually exclusive

Q: A company believes that it controls more than 30% of the total market share for one of its products. To prove this belief, a random sample of 144 purchases of this product is contacted. It is found that 50 of the 144 purchased this company's brand of the product. If a researcher wants to conduct a statistical test for this problem, the test would be _______. a) a one-tailed test b) a two-tailed test c) an alpha test d) a finite population test e) a finite sample test

Q: A company believes that it controls more than 30% of the total market share for one of its products. To prove this belief, a random sample of 144 purchases of this product is contacted. It is found that 50 of the 144 purchased this company's brand of the product. If a researcher wants to conduct a statistical test for this problem, the observed zvalue would be _______. a) 0.05 b) 0.103 c) 0.35 d) 1.24 e) 1.67

Q: A company believes that it controls more than 30% of the total market share for one of its products. To prove this belief, a random sample of 144 purchases of this product is contacted. It is found that 50 of the 144 purchased this company's brand of the product. If a researcher wants to conduct a statistical test for this problem, the alternative hypothesis would be _______. a) the population proportion is less than 0.30 b) the population proportion is greater than 0.30 c) the population proportion is not equal to 0.30 d) the population mean is less than 40 e) the population mean is greater than 40

Q: A political scientist wants to prove that a candidate is currently carrying more than 60% of the vote in the state. She has her assistants randomly sample 200 eligible voters in the state by telephone and only 90 declare that they support her candidate. The observed zvalue for this problem is _______. a) -4.33 b) 4.33 c) 0.45 d) -.31 e) 2.33

Q: The weight of a USB flash drive is 30 grams and is normally distributed. Periodically, quality control inspectors at Dallas Flash Drives randomly select a sample of 17 USB flash drives. If the mean weight of the USB flash drives is too heavy or too light the machinery is shut down for adjustment; otherwise, the production process continues. The last sample showed a mean and standard deviation of 31.9 and 1.8 grams, respectively. Using = 0.10, the appropriate decision is _______. a) reject the null hypothesis and shut down the process b) reject the null hypothesis and do not shut down the process c) fail to reject the null hypothesis and shut down the process d) fail to reject the null hypothesis and do not shut down the processe) do nothing

Q: The weight of a USB flash drive is 30 grams and is normally distributed. Periodically, quality control inspectors at Dallas Flash Drives randomly select a sample of 17 USB flash drives. If the mean weight of the USB flash drives is too heavy or too light the machinery is shut down for adjustment; otherwise, the production process continues. The last sample showed a mean and standard deviation of 31.9 and 1.8 grams, respectively. . The null hypothesis is ______. a) n 17 b) n= 17 c) = 30 d) 30 e) m≥34.9

Q: The weight of a USB flash drive is 30 grams and is normally distributed. Periodically, quality control inspectors at Dallas Flash Drives randomly select a sample of 17 USB flash drives. If the mean weight of the USB flash drives is too heavy or too light the machinery is shut down for adjustment; otherwise, the production process continues. The last sample showed a mean and standard deviation of 31.9 and 1.8 grams, respectively. Using = 0.10, the critical "t" values are _______. a) -2.120 and 2.120 b) -2.131 and 2.131 c) -1.753 and 1.753 d) -1.746 and 1.746 e) -2.567 and 2.567

Q: A coffee-dispensing machine is supposed to deliver 8 ounces of liquid into each paper cup, but a consumer believes that the actual mean amount is less. The consumer obtained a sample of 16 cups of the dispensed liquid with sample mean of 7.75 ounces and sample variance of 0.81 ounces. If the dispensed liquid delivered per cup is normally distributed, the appropriate decision at α=0.05 is a) increase the sample size b) reduce the sample size c) fail to reject the 8-ounces claim d) maintain status quo e) reject the 8-ounces claim

Q: The local oil changing business is very busy on Saturday mornings and is considering expanding. A national study of similar businesses reported the mean number of customers waiting to have their oil changed on Saturday morning is 3.6. Suppose the local oil changing business owner, wants to perform a hypothesis test. The null hypothesis is the population mean is 3.6 and the alternative hypothesis is the population mean is not equal to 3.6. The owner takes a random sample of 16 Saturday mornings during the past year and determines the sample mean is 4.2 and the sample standard deviation is 1.4. It can be assumed that the population is normally distributed. The level of significance is 0.05. The decision rule for this problem is to reject the null hypothesis if the observed "t" value is _______. a) less than -2.131 or greater than 2.131 b) less than -1.761 or greater than 1.761 c) less than -1.753 or greater than 1.753 d) less than -2.120 or greater than 2.120 e) less than -3.120 or greater than 3.120

Q: The local oil changing business is very busy on Saturday mornings and is considering expanding. A national study of similar businesses reported the mean number of customers waiting to have their oil changed on Saturday morning is 3.6. Suppose the local oil changing business owner, wants to perform a hypothesis test. The null hypothesis is the population mean is 3.6 and the alternative hypothesis that the population mean is not equal to 3.6. The owner takes a random sample of 16 Saturday mornings during the past year and determines the sample mean is 4.2 and the sample standard deviation is 1.4. It can be assumed that the population is normally distributed and the level of significance is 0.05. The table "t" value for this problem is _______.a) 1.753b) 2.947c) 2.120d) 2.131e) 2.311

Q: The local oil changing business is very busy on Saturday mornings and is considering expanding. A national study of similar businesses reported the mean number of customers waiting to have their oil changed on Saturday morning is 3.6. Suppose the local oil changing business owner, wants to perform a hypothesis test. The null hypothesis is the population mean is 3.6 and the alternative hypothesis that the population mean is not equal to 3.6. The owner takes a random sample of 16 Saturday mornings during the past year and determines the sample mean is 4.2 and the sample standard deviation is 1.4. It can be assumed that the population is normally distributed. The observed "t" value for this problem is _______. a) 0.05 b) 0.43 c) 1.71 d) 1.33 e) 0.71

Q: Suppose a researcher is testing a null hypothesis that m= 61. A random sample of n= 36 is taken resulting in a sample mean of 63 and s = 9. The observed tvalue is _______. a) -0.22 b) 0.22 c) 1.33 d) 8.08 e) 7.58

Q: In performing hypothesis tests about the population mean, if the population standard deviation is not known, a ttest can be used to test the mean if _________________.a) n is smallb) the sample is randomc) the population mean is knownd) the population is normally distributede) the population is chi-square distributed

Q: In performing a hypothesis test where the null hypothesis is that the population mean is 4.8 against the alternative hypothesis that the population mean is not equal to 4.8, a random sample of 25 items is selected. The sample mean is 4.1 and the sample standard deviation is 1.4. It can be assumed that the population is normally distributed. The observed "t" value for this problem is _______. a) -12.5 b) 12.5 c) -2.5 d) -0.7 e) 0.7

Q: In performing a hypothesis test where the null hypothesis is that the population mean is 4.8 against the alternative hypothesis that the population mean is not equal to 4.8, a random sample of 25 items is selected. The sample mean is 4.1 and the sample standard deviation is 1.4. It can be assumed that the population is normally distributed. The level of significance is selected to be 0.10. The table "t" value for this problem is _______. a) 1.318 b) 1.711 c) 2.492 d) 2.797 e) 3.227

Q: In performing a hypothesis test where the null hypothesis is that the population mean is 4.8 against the alternative hypothesis that the population mean is not equal to 4.8, a random sample of 25 items is selected. The sample mean is 4.1 and the sample standard deviation is 1.4. It can be assumed that the population is normally distributed. The degrees of freedom associated with this are _______. a) 25 b) 24 c) 26 d) 2 e) 1

Q: In performing a hypothesis test where the null hypothesis is that the population mean is 23 against the alternative hypothesis that the population mean is not equal to 23, a random sample of 17 items is selected. The sample mean is 24.6 and the sample standard deviation is 3.3. It can be assumed that the population is normally distributed. The degrees of freedom associated with this are _______. a) 17 b) 16 c) 15 d) 2 e) 1

Q: Jennifer Cantu, VP of Customer Services at Tri-State Auto Insurance, Inc., monitors the claims processing time of the claims division. Her standard includes "a mean processing time of 5 days or less." Each week, her staff checks for compliance by analyzing a random sample of 60 claims. Jennifer's null hypothesis is ________. a) > 5 b) > 5 c) n= 60 d) < 5 e) =5

Q: A home building company routinely orders standard interior doors with a height of 80 inches. Recently the installers have complained that the doors are not the standard height. The quality control inspector for the home building company is concerned that the manufacturer is supplying doors that are not 80 inches in height. In an effort to test this, the inspector is going to gather a sample of the recently received doors and measure the height. The alternative hypothesis for the statistical test to determine if the doors are not 80 inches is a) the mean height is > 80 inches b) the mean height is < 80 inches c) the mean height is = 80 inches d) the mean height is ≠80 inches e) the mean height is ≥80 inches

Q: The local swim team is considering offering a new semi-private class aimed at entry-level swimmers, but needs a minimum number of swimmers to sign up in order to be cost effective. Last year's data showed that during 8 swim sessions the average number of entry-level swimmers attending was 15. Suppose the instructor wants to conduct a hypothesis test and the alternative hypothesis is "the population mean is greater than 15"If the sample size is 5, sis known, and alpha = .01, the critical value of zis _______.a) 2.575b) -2.575c) 2.33d) -2.33e) 2.45

Q: The local swim team is considering offering a new semi-private class aimed at entry-level swimmers, but needs at minimum number of swimmers to sign up in order to be cost effective. Last year's data showed that during 8 swim sessions the average number of entry-level swimmers attending was 15. Suppose the instructor wants to conduct a hypothesis test. The alternative hypothesis for this hypothesis test is: "the population mean is less than 15". The sample size is 8, sis known, and alpha =.05, the critical value of zis _______. a) 1.645 b) -1.645 c) 1.96 d) -1.96 e) 2.05

Q: A coffee-dispensing machine is supposed to deliver 8 ounces of liquid into each paper cup, but a consumer believes that the actual mean amount is less. The consumer obtained a sample of 49 cups of the dispensed liquid with average of 7.75 ounces. If the sample variance of the dispensed liquid delivered per cup is 0.81 ounces, and α=0.05, the appropriate decision is ________. a) increase the sample size b) reduce the sample size c) fail to reject the 8-ounces claim d) maintain status quo e) reject the 8-ounces claim

Q: A researcher is testing a hypothesis of a single mean. The critical zvalue for = .05 and a two"‘tailed test is +1.96. The observed zvalue from sample data is -2.11. The decision made by the researcher based on this information is to _____ the null hypothesis.a) rejectb) fail to rejectc) redefined) change the alternate hypothesis intoe) restate the null hypothesis

Q: A researcher is testing a hypothesis of a single mean. The critical zvalue for = .05 and a two"‘tailed test is +1.96. The observed zvalue from sample data is 2.85. The decision made by the researcher based on this information is to _____ the null hypothesis. a) reject b) fail to reject c) redefine d) change the alternate hypothesis into e) restate the null hypothesis

Q: A researcher is testing a hypothesis of a single mean. The critical zvalue for = .05 and a two"‘tailed test is +1.96. The observed zvalue from sample data is "‘1.85. The decision made by the researcher based on this information is to _____ the null hypothesis. a) reject b) fail to reject c) redefine d) change the alternate hypothesis into e) restate the null hypothesis

Q: A researcher is testing a hypothesis of a single mean. The critical zvalue for = .05 and an one"‘tailed test is 1.645. The observed zvalue from sample data is 1.13. The decision made by the researcher based on this information is to ______ the null hypothesis. a) reject b) fail to reject c) redefine d) change the alternate hypothesis into e) restate the null hypothesis

Q: Suppose you are testing the null hypothesis that a population mean is greater than or equal to 60, against the alternative hypothesis that the population mean is less than 60. The sample size is 64 and = .05. If the sample mean is 58 and the population standard deviation is 16, the observed zvalue is _______. a) -1 b) 1 c) -8 d) 8 e) 58

Q: Suppose you are testing the null hypothesis that a population mean is less than or equal to 46, against the alternative hypothesis that the population mean is greater than 46. The sample size is 25 and alpha =.05. If the sample mean is 50 and the population standard deviation is 8, the observed zvalue is _______. a) 2.5 b) -2.5 c) 6.25 d) -6.25 e) 12.5

Q: Suppose you are testing the null hypothesis that a population mean is less than or equal to 46, against the alternative hypothesis that the population mean is greater than 46. If the sample size is 25, sis known, and alpha = .01, the critical value of zis _______. a) 1.645 b) -1.645 c) 1.28 d) -2.33 e) 2.33

Q: In a two-tailed hypothesis about a population mean with a sample size of 100, sis known, and α= 0.05, the rejection region would be _______. a) z> 1.64 b) z> 1.96 c) z< -1.96 and z> 1.96 d) z< -1.64 and z> 1.64 e) z < -2.33 and z > 2.33

Q: In a two-tailed hypothesis about a population mean with a sample size of 100, sis known, and alpha = 0.10, the rejection region would be _______. a) z > 1.64 b) z > 1.28 c) z < -1.28 and z > 1.28 d) z < -1.64 and z > 1.64 e) z < -2.33 and z > 2.33