Q&A Hero

Q: Three events occur with probabilities P(E1) = 0.35, P(E2) = 0.15, P(E3) = 0.40. If the event B occurs, the probability becomes P(E1|B) = 0.25, P(B) = 0.30. Compute P(E1 or B). A) 0.575 B) 0.075 C) 0.021 D) 0.475

Q: Three events occur with probabilities P(E1) = 0.35, P(E2) = 0.15, P(E3) = 0.40. If the event B occurs, the probability becomes P(E1|B) = 0.25, P(B) = 0.30. Calculate P(E1 and B). A) 0.575 B) 0.075 C) 0.021 D) 0.475

Q: Micron Technology has sales offices located in four cities: Dallas, Seattle, Boston, and Los Angeles. An analysis of the company's accounts receivables reveals the number of overdue invoices by days, as shown here. Days Overdue Dallas Seattle Boston Los Angeles Under 30 days 137 122 198 287 30-60 days 85 46 76 109 61-90 days 33 27 55 48 Over 90 days 18 32 45 66 Assume the invoices are stored and managed from a central database. If a randomly selected invoice is from the Los Angeles office, what is the probability that it is 60 or fewer days overdue? A) 0.2702 B) 0.0231 C) 0.3461 D) 0.7765

Q: Micron Technology has sales offices located in four cities: Dallas, Seattle, Boston, and Los Angeles. An analysis of the company's accounts receivables reveals the number of overdue invoices by days, as shown here. Days Overdue Dallas Seattle Boston Los Angeles Under 30 days 137 122 198 287 30-60 days 85 46 76 109 61-90 days 33 27 55 48 Over 90 days 18 32 45 66 Assume the invoices are stored and managed from a central database. What is the probability that a randomly selected invoice from the database is over 90 days old and from the Seattle office? A) 0.2702 B) 0.0231 C) 0.3461 D) 0.7765

Q: Micron Technology has sales offices located in four cities: Dallas, Seattle, Boston, and Los Angeles. An analysis of the company's accounts receivables reveals the number of overdue invoices by days, as shown here. Days Overdue Dallas Seattle Boston Los Angeles Under 30 days 137 122 198 287 30-60 days 85 46 76 109 61-90 days 33 27 55 48 Over 90 days 18 32 45 66 Assume the invoices are stored and managed from a central database. What is the probability that a randomly selected invoice from the database is between 30 and 90 days overdue? A) 0.2702 B) 0.0231 C) 0.3461 D) 0.7765

Q: Micron Technology has sales offices located in four cities: Dallas, Seattle, Boston, and Los Angeles. An analysis of the company's accounts receivables reveals the number of overdue invoices by days, as shown here. Days Overdue Dallas Seattle Boston Los Angeles Under 30 days 137 122 198 287 30-60 days 85 46 76 109 61-90 days 33 27 55 48 Over 90 days 18 32 45 66 Assume the invoices are stored and managed from a central database. What is the probability that a randomly selected invoice from the database is from the Boston sales office? A) 0.2702 B) 0.0231 C) 0.3461 D) 0.7765

Q: The college basketball team at West Texas State University has 10 players; 5 are seniors, 2 are juniors, and 3 are sophomores. Two players are randomly selected to serve as captains for the next game. What is the probability that both players selected are seniors? A) 0.22 B) 0.33 C) 0.50 D) 0.66

Q: Ponderosa Paint and Glass carries three brands of paint. A customer wants to buy another gallon of paint to match paint she purchased at the store previously. She can't recall the brand name and does not wish to return home to find the old can of paint. So she selects two of the three brands of paint at random and buys them. Her husband also goes to the paint store and fails to remember what brand to buy. So he also purchases two of the three brands of paint at random. Determine the probability that both the woman and her husband fail to get the correct brand of paint. (Hint: Are the husband's selections independent of his wife's selections?) A) 3/2 B) 2/3 C) 1/9 D) 3/4

Q: Ponderosa Paint and Glass carries three brands of paint. A customer wants to buy another gallon of paint to match paint she purchased at the store previously. She can't recall the brand name and does not wish to return home to find the old can of paint. So she selects two of the three brands of paint at random and buys them. What is the probability that she matched the paint brand? A) 3/2 B) 2/3 C) 1/9 D) 3/4

Q: The Jack In The Box franchise in Bangor, Maine, has determined that the chance a customer will order a soft drink is 0.90. The probability that a customer will order a hamburger is 0.60. The probability that a customer will order french fries is 0.50. The restaurant has also determined that if a customer orders a hamburger, the probability the customer will also order fries is 0.80. Determine the probability that the order will include a hamburger and fries. A) 0.45 B) 0.58 C) 0.68 D) 0.48

Q: The Jack In The Box franchise in Bangor, Maine, has determined that the chance a customer will order a soft drink is 0.90. The probability that a customer will order a hamburger is 0.60. The probability that a customer will order french fries is 0.50. If a customer places an order, what is the probability that the order will include a soft drink and no fries if these two events are independent? A) 0.45 B) 0.50 C) 0.65 D) 0.70

Q: Based on weather data collected in Racine, Wisconsin, on Christmas Day, the weather had the following distribution: Event Relative Frequency Clear & dry 0.20 Cloudy & dry 0.30 Rain 0.40 Snow 0.10 Supposing next Christmas is dry, determine the probability that it will also be cloudy. A) 0.45 B) 0.50 C) 0.60 D) 0.70

Q: Based on weather data collected in Racine, Wisconsin, on Christmas Day, the weather had the following distribution: Event Relative Frequency Clear & dry 0.20 Cloudy & dry 0.30 Rain 0.40 Snow 0.10 Based on the data, what is the probability that next Christmas will be rainy or cloudy and dry? A) 0.45 B) 0.50 C) 0.60 D) 0.70

Q: Based on weather data collected in Racine, Wisconsin, on Christmas Day, the weather had the following distribution: Event Relative Frequency Clear & dry 0.20 Cloudy & dry 0.30 Rain 0.40 Snow 0.10 /Thompson_sn3t_WordExports/Thompson_sn3t_WordExports Based on these data, what is the probability that next Christmas will be dry? A) 0.45 B) 0.50 C) 0.60 D) 0.70

Q: Cross County Bicycles makes two mountain bike models that each come in three colors. The following table shows the production volumes for last week: What is the joint probability that a product manufactured is a YZ-99 and brown? A) 0.2088 B) 0.3819 C) 0.3157 D) 0.1324

Q: Cross County Bicycles makes two mountain bike models that each come in three colors. The following table shows the production volumes for last week: What is the probability that the product manufactured is a YZ-99? A) 0.2088 B) 0.3819 C) 0.3157 D) 0.1324

Q: Cross County Bicycles makes two mountain bike models that each come in three colors. The following table shows the production volumes for last week: Based on the relative frequency assessment method, what is the probability that a manufactured item is brown? A) 0.2088 B) 0.3819 C) 0.3157 D) 0.1324

Q: The results of a census of 2,500 employees of a mid-sized company with 401(k) retirement accounts are as follows: Account Balance (to nearest $) Male Female $25,000 635 495 $25,000-$49,999 185 210 $50,000-$99,999 515 260 $100,000 155 45 Suppose researchers are going to sample employees from the company for further study. Compute the probability that a randomly selected employee will be a female with an account balance between $50,000 and $99,999. A) 0.1580 B) 0.1040 C) 0.6160 D) 0.4040

Q: The results of a census of 2,500 employees of a mid-sized company with 401(k) retirement accounts are as follows: Account Balance (to nearest $) Male Female $25,000 635 495 $25,000-$49,999 185 210 $50,000-$99,999 515 260 $100,000 155 45 Suppose researchers are going to sample employees from the company for further study. Based on the relative frequency assessment method, what is the probability that a randomly selected employee will have a 401(k) account balance of between $25,000 and $49,999? A) 0.1580 B) 0.1040 C) 0.6160 D) 0.4040

Q: The results of a census of 2,500 employees of a mid-sized company with 401(k) retirement accounts are as follows: Account Balance (to nearest $) Male Female $25,000 635 495 $25,000-$49,999 185 210 $50,000-$99,999 515 260 $100,000 155 45 Suppose researchers are going to sample employees from the company for further study. Based on the relative frequency assessment method, what is the probability that a randomly selected employee will be a female? A) 0.1580 B) 0.1040 C) 0.6160 D) 0.4040

Q: Students who live on campus and purchase a meal plan are randomly assigned to one of three dining halls: the Commons, Northeast, and Frazier. What is the probability that the next student to purchase a meal plan will be assigned to the Commons? A) 0.66 B) 0.5 C) 0.25 D) 0.33

Q: Long-time friends, Pat and Tom, agree on many things, but not the outcome of the American League pennant race and the World Series. Pat is originally from Boston, and Tom is from New York. They have a steak dinner bet on next year's race, with Pat betting on the Red Sox and Tom on the Yankees. Both are convinced they will win. What probability assessment technique is being used by the two friends? A) Subjective probability B) Classical probability C) Relative frequency probability D) Independent probability

Q: An inventory of appliances contains four white washers and one black washer. If a customer selects one at random, what is the probability that the black washer will be selected? A) 0.5 B) 0.4 C) 0.2 D) 0.8

Q: What method of probability assessment would most likely be used to assess the probability that a customer will return a purchase for a refund? A) Classical probability based on the ratio of the number of ways the event can occur B) Relative frequency based on previous history C) Subjective probability based on expert opinion D) Independent probability based on two unrelated outcomes

Q: What method of probability assessment would most likely be used to assess the probability that a major earthquake will occur in California in the next three years? A) Classical probability based on the ratio of the number of ways the event can occur B) Relative frequency based on previous history C) Subjective probability based on expert opinion D) Independent probability based on two unrelated outcomes

Q: In a survey, respondents were asked to indicate their favorite brand of cereal (Post or Kellogg's). They were allowed only one choice. What is the probability concept that implies it is not possible for a single respondent to state both Post and Kellogg's to be the favorite cereal? A) Concept of independent events B) Concept of mutually exclusive events C) Concept of dependent events D) Concept of mutually inclusive events

Q: A special roulette wheel, which has an equal number of red and black spots, has come up red four times in a row. Assuming that the roulette wheel is fair, what concept allows a player to know that the probability the next spin of the wheel will come up black is 0.5? A) Concept of independent events B) Concept of mutually exclusive events C) Concept of dependent events D) Concept of mutually inclusive events

Q: Of the last 100 customers entering a computer shop, 25 have purchased a computer. If the classical probability assessment for computing probability is used, the probability that the next customer will purchase a computer is: A) 0.25 B) 0.50 C) 1.00 D) 0.75

Q: Harrison Water Sports has three retail outlets: Seattle, Portland, and Phoenix. The Seattle store does 50 percent of the total sales in a year, while the Portland store does 35 percent of the total sales. Further analysis indicates that of the sales in Seattle, 20 percent are in boat accessories. The percentage of boat accessories at the Portland store is 30 and the percentage at the Phoenix store is 25. Overall, the probability that a sale by Harrison Water Sports will be for a boat accessory is: A) 0.105 B) 0.2425 C) 0.75 D) None of the above

Q: Harrison Water Sports has three retail outlets: Seattle, Portland, and Phoenix. The Seattle store does 50 percent of the total sales in a year, while the Portland store does 35 percent of the total sales. Further analysis indicates that of the sales in Seattle, 20 percent are in boat accessories. The percentage of boat accessories at the Portland store is 30 and the percentage at the Phoenix store is 25. If a sales dollar is recorded as a boat accessory, the probability that the sale was made at the Portland store is: A) slightly greater than 0.43 B) 0.35 C) 0.2425 D) None of the above

Q: The Anderson Lumber Company has three sawmills that produce boards of different lengths. The following table is a joint frequency distribution based on a random sample of 1000 boards selected from the lumber inventory. Based on these data, if three boards are selected at random, the probability that all three were made at sawmill A is: A) 0.037 B) 0.334 C) 1.00 D) 0.556

Q: The Anderson Lumber Company has three sawmills that produce boards of different lengths. The following table is a joint frequency distribution based on a random sample of 1,000 boards selected from the lumber inventory. Based on these data, if a board is selected that is 12 feet long, the probability that it was made at sawmill A is: A) 0.08 B) 0.41 C) 0.24 D) 0.20

Q: What is meant by the concept, standardizing the data? Explain why a decision maker may wish to compute a standardized value.

Q: Consumer products are required by law to contain at least as much as the amount printed on the package. For example a bag of potato chips that is labeled as 10 ounces should contain at least 10 ounces. Assume that the standard deviation of the packaging equipment yields a bag weight standard deviation of 0.2 ounces. Explain what average bag weight must be used to achieve at least 97.5 percent of the bags having 10 or more ounces in the bag. Assume the bag weight distribution is bell-shaped.

Q: Explain what is meant by percentiles and quartiles.

Q: Explain how Tchebysheff's theorem can be used to help describe data in a population or a sample.

Q: Explain how the empirical rule can be used to help describe data in a population or a sample.

Q: Why is it that when we find the sample standard deviation, we divide by n-1 but when we find the population standard deviation we divide by n?

Q: The following sample data reflect electricity bills for ten households in San Diego in March. $118.20 $67.88 $133.40 $88.42 $110.34 $76.90 $144.56 $127.89 $89.34 $129.10 Compute the range, variance, and standard deviation for these sample data. Discuss which of these three measures you would prefer to use as a measure of variation.

Q: The following sample data reflect electricity bills for ten households in San Diego in March. $118.20 $67.88 $133.40 $88.42 $110.34 $76.90 $144.56 $127.89 $89.34 $129.10 Determine three measures of central tendency for these sample data. Then, based on these measures, determine whether the sample data are symmetric or skewed.

Q: The AMI Company has two assembly lines in its Kansas City plant. Line A produces an average of 335 units per day with a standard deviation equal to 11 units. Line B produces an average of 145 units per day with a standard deviation equal to 8 units. Based on this information, which line is relatively more consistent?

Q: Suppose that the distribution of grocery purchases is thought to be symmetric. If the mean purchase is $23.14, what would the median purchase be?

Q: Dynamic random-access memory (DRAM) memory chips are made from silicon wafers in manufacturing facilities through a very complex process called wafer fabs. The wafers are routed through the fab machines in an order that is referred to as a recipe. The wafers may go through the same machine several times as the chip is created. The data file DRAM Chips contains a sample of processing times, measured in fractions of hours, at a particular machine center for one chip recipe. Calculate the 80th percentile for processing time. A) 0.40 minutes B) 0.35 minutes C) 0.45 minutes D) 0.20 minutes

Q: Dynamic random-access memory (DRAM) memory chips are made from silicon wafers in manufacturing facilities through a very complex process called wafer fabs. The wafers are routed through the fab machines in an order that is referred to as a recipe. The wafers may go through the same machine several times as the chip is created. The data file DRAM Chips contains a sample of processing times, measured in fractions of hours, at a particular machine center for one chip recipe. Determine what the mode processing time is. A) 0.22 B) 0.24 C) 0.33 D) 0.34

Q: Dynamic random-access memory (DRAM) memory chips are made from silicon wafers in manufacturing facilities through a very complex process called wafer fabs. The wafers are routed through the fab machines in an order that is referred to as a recipe. The wafers may go through the same machine several times as the chip is created. The data file DRAM Chips contains a sample of processing times, measured in fractions of hours, at a particular machine center for one chip recipe. Compute the median processing time. A) 0.31 minutes B) 0.24 minutes C) 0.21 minutes D) 0.44 minutes

Q: Dynamic random-access memory (DRAM) memory chips are made from silicon wafers in manufacturing facilities through a very complex process called wafer fabs. The wafers are routed through the fab machines in an order that is referred to as a recipe. The wafers may go through the same machine several times as the chip is created. The data file DRAM Chips contains a sample of processing times, measured in fractions of hours, at a particular machine center for one chip recipe. Compute the mean processing time. A) 0.24 minutes B) 0.22 minutes C) 0.31 minutes D) 0.33 minutes

Q: Each year, Business Week publishes information and rankings of master of business administration (MBA) programs. The data file MBA Analysis contains data on several variables for eight reputable MBA programs as presented in the October 2, 2000, issue of Business Week. The variables include pre- and post-MBA salary, percentage salary increase, undergraduate GPA, average Graduate Management Admission Test (GMAT) score, annual tuition, and expected annual student cost. Compute the mean and median for each of the variables in the database. A) Mean Median Pre-MBA Salary 39077 43337.63 Post-MBA Salary 82203 98902 Percentage Increase in Salary 116 123 Undergraduate GPA 3.46 3.40 GMAT Score 635.00 631.13 Annual Tuition 13163.50 15967.50 Expected Annual Student Cost 23169.5 27980.75 B) Mean Median Pre-MBA Salary 46667.63 39077 Post-MBA Salary 98902 84403 Percentage Increase in Salary 113 116 Undergraduate GPA 3.40 3.56 GMAT Score 661.16 635.00 Annual Tuition 15967.50 19163.70 Expected Annual Student Cost 28980.75 23179.5 C) Mean Median Pre-MBA Salary 43337.63 39077 Post-MBA Salary 98902 82203 Percentage Increase in Salary 123 116 Undergraduate GPA 3.40 3.46 GMAT Score 631.13 635.00 Annual Tuition 15967.50 13163.50 Expected Annual Student Cost 27980.75 23169.5 D) Mean Median Pre-MBA Salary 39077 46667.63 Post-MBA Salary 84403 98902 Percentage Increase in Salary 116 113 Undergraduate GPA 3.56 3.40 GMAT Score 635.00 661.16 Annual Tuition 19163.70 15967.50 Expected Annual Student Cost 23179.5 28980.75

Q: Todd Lindsey & Associates, a commercial real estate company located in Boston, owns six office buildings in the Boston area that it leases to businesses. The lease price per square foot differs by building due to location and building amenities. Currently, all six buildings are fully leased at the prices shown here. Price per Square Foot Number of Square Feet Building 1 $ 75 125,000 Building 2 $ 85 37,500 Building 3 $ 90 77,500 Building 4 $ 45 35,000 Building 5 $ 55 60,000 Building 6 $110 130,000 Compute the weighted average (mean) price per square foot for these buildings. A) 86.25 B) 83.25 C) 80.15 D) 86.15

Q: A professor wishes to develop a numerical method for giving grades. He intends to base the grade on homework, two midterms, a project, and a final examination. He wishes the final exam to have the largest influence on the grade. He wants the project to have 10%, each midterm to have 20%, and the homework to have 10% of the influence of the semester grade. For a student with the following grades during the quarter, calculate a weighted average for the course: Instrument Final Project Midterm 1 Modterm 2 Homework Percentage Grade 64 98 67 63 89 A) 68.50 B) 73.30 C) 68.30 D) 70.30

Q: A professor wishes to develop a numerical method for giving grades. He intends to base the grade on homework, two midterms, a project, and a final examination. He wishes the final exam to have the largest influence on the grade. He wants the project to have 10%, each midterm to have 20%, and the homework to have 10% of the influence of the semester grade. Determine the weights the professor should use to produce a weighted average for grading purposes. A) Instrument Final Project Midterm 1 Midterm 2 Homework Weight 40 10 20 20 10 B) Instrument Final Project Midterm 1 Midterm 2 Homework Weight 50 10 20 20 10 C) Instrument Final Project Midterm 1 Midterm 2 Homework Weight 40 15 15 15 15 D) Instrument Final Project Midterm 1 Midterm 2 Homework Weight 30 10 20 20 10

Q: The Empirical Rule states that for a bell-shaped distribution, approximately 95 percent of data should lie within: A) one standard deviation from either side of the mean. B) two standard deviations from either side of the mean. C) three standard deviations from either side of the mean. D) four standard deviations from either side of the mean.

Q: When comparing data measured by substantially different scales, we must use: A) standardized data values. B) standardized data scales. C) standardized data variations. D) standardized data scores.

Q: Portfolio A of a collection of stocks is considered more risky than portfolio B if: A) portfolio A has a higher mean than portfolio B. B) portfolio A has a higher variance than portfolio B. C) portfolio A has a higher standard deviation. D) portfolio A has a higher coefficient of variation than portfolio B.

Q: Data was collected on the number of television sets in a household, and it was found that the mean was 3.5 and the standard deviation was 0.75. Based on these sample data, what is the standardized value corresponding to 5 televisions? A) -2.00 B) 1.5 C) 2.00 D) 1.125

Q: A recent study in the restaurant business determined that the mean tips for male waiters per hour of work are $6.78 with a standard deviation of $2.11. The mean tips per hour for female waiters are $7.86 with a standard deviation of $2.20. Based on this information, which of the following statements do we know to be true? A) The distribution of tips for both males and females is right-skewed. B) The variation in tips received by females is more variable than males. C) The median tips for females exceeds that of males. D) On a relative basis, males have more variation in tips per hour than do females.

Q: The distribution of the actual weight of potato chips in a 16 ounce sack is thought to be bell-shaped with a mean equal to 16 ounces and a standard deviation equal to 0.45 ounces. Based on this, between what two limits could we expect 95 percent of all sacks to weigh? A) 14 to 18 ounces B) 15.10 to 16.90 ounces C) 15.55 to 16.45 ounces D) 14.65 to 17.35 ounces

Q: A report on spending by adults on recreation stated the following: At least 75 percent of the people in the survey spend between $750 and $1,250 per year. The report also said that at least 88 percent spend between $625 and $1,375 per year. Given this information, which of the following is most apt to be true? A) The standard deviation is approximately $125. B) The distribution of spending on recreation can be assumed to be bell-shaped. C) The standard deviation is approximately $187.5. D) The standard deviation is approximately $250.

Q: The asking price for homes on the real estate market in Baltimore has a mean value of $286,455 and a standard deviation of $11,200. The mean and standard deviation in asking price for homes in Denver are $188,468 and $8,230, respectively. Recently, one home sold in each city where the asking price for each home was $193,000. Assuming that both distributions are bell-shaped, which of the following statements is true? A) The Baltimore home has the higher standard z-value. B) The coefficient of variation for Denver is less than for Baltimore. C) The Denver home has a higher standard z-value. D) Both cities have the same coefficient of variation.

Q: The asking price for homes on the real estate market in Baltimore has a mean value of $286,455 and a standard deviation of $11,200. The mean and standard deviation in asking price for homes in Denver are $188,468 and $8,230, respectively. Recently, one home sold in each city where the asking price for each home was $193,000. Based on these data, which of the following conclusions can be made? A) The two homes have approximately the same standardized values. B) The distribution of asking prices in the two cities is bell-shaped. C) The house in Baltimore is relatively farther from the mean than the house in Denver. D) The asking prices of homes in Denver is less variable than those in Baltimore.

Q: The asking price for homes on the real estate market in Baltimore has a mean value of $286,455 and a standard deviation of $11,200. Four homes are listed by one real estate company with the following prices: Home 1: $456,900 Home 2: $306,000 Home 3: $266,910 Home 4: $201,456 Based upon this information, which house has a standardized value that is relatively closest to zero? A) Home 1 B) Home 2 C) Home 3 D) Home 2 and home 3

Q: A distribution has a coefficient of variation of 65 percent and mean of 74. What is the value of the standard deviation? A) 0.65 B) 4810 C) 113.8 D) 48.1

Q: Incomes in a particular market area are known to be right-skewed with a mean equal to $33,100. In a report issued recently, a manager stated that at least 89 percent of all incomes are in the range of $26,700 to $39,500, and this was based on Tchebysheff's theorem. Given these facts, what is the standard deviation for the incomes in this market area? A) Approximately $6,400 B) Approximately $3,200 C) Approximately $2,133 D) Approximately $4266

Q: The number of days that homes stay on the market before they sell in Houston is bell-shaped with a mean equal to 56 days. Further, 95 percent of all homes are on the market between 40 and 72 days. Based on this information, what is the standard deviation for the number of days that houses stay on the market in Houston? A) 8 B) C) 16 D) 4

Q: In the annual report, a major food chain stated that the distribution of daily sales at its Detroit stores is known to be bell-shaped, and that 95 percent of all daily sales fell between $19,200 and $36,400. Based on this information, what were the mean sales? A) Around $20,000 B) Close to $30,000 C) Approximately $27,800 D) Can't be determined without more information.

Q: Under what circumstances is it necessary to use the coefficient of variation to compare relative variability between two or more distributions? A) When the means of the distributions are equal B) When the means of the distributions are not equal C) When the standard deviations of the distributions are not equal D) When the standard deviations of the distributions are equal

Q: If the age distribution of customers at a major retail chain is thought to be bell-shaped with a mean equal to 43 years and a standard deviation equal to 7 years, the percentage of customers between the ages of 29 and 57 years is: A) approximately 81.5. B) approximately 68. C) at least 75. D) approximately 95.

Q: Consider the following data, which represent the number of miles that employees commute from home to work each day. There are two samples: one for males and one for females. Males: 13 5 2 23 14 5 Females: 15 6 3 2 4 6 Which of the following statements is true? A) Females have the larger mean. B) The coefficient of variation is larger for females than for males. C) The coefficient of variation is larger for males than for females. D) Females have the larger range.

Q: Consider the following data, which represent the number of miles that employees commute from home to work each day. There are two samples: one for males and one for females. Males: 13 5 2 23 14 5 Females: 15 6 3 2 4 6 The coefficient of variation of commute miles for the males is: A) approximately 76 percent. B) about 7.8. C) approximately 61.5. D) about 67 percent.

Q: Consider the following data, which represent the number of miles that employees commute from home to work each day. There are two samples: one for males and one for females. Males: 13 5 2 23 14 5 Females: 15 6 3 2 4 6 Which of the following statements is true? A) The female distribution is more variable since the range for the females is greater than for the males. B) Females in the sample commute farther on average than do males. C) The males in the sample commute farther on average than the females. D) Males and females on average commute the same distance.

Q: In order to compute the mean and standard deviation, the level of data measurement should be: A) ratio or interval. B) qualitative. C) nominal. D) ordinal.

Q: The following data reflect the number of customers who return merchandise for a refund on Monday. Note these data reflect the population of all 10 Mondays for which data are available. 40 12 17 25 9 46 13 22 16 7 Assume that this same exact pattern of data were replicated for the next ten days. How would this affect the standard deviation for the new population with 20 items? A) The standard deviation would be doubled. B) The standard deviation would be cut in half. C) The standard deviation would not be changed. D) There is no way of knowing the exact impact without knowing how the mean is changed.

Q: The following data reflect the number of customers who return merchandise for a refund on Monday. Note these data reflect the population of all 10 Mondays for which data are available. 40 12 17 25 9 46 13 22 16 7 Based on these data, what is the standard deviation? A) 13.03 B) 12.36 C) 39 D) 152.8

Q: The advantage of using the interquartile range versus the range as a measure of variation is: A) it is easier to compute. B) it utilizes all the data in its computation. C) it gives a value that is closer to the true variation. D) it is less affected by extremes in the data.

Q: The following data reflect the number of customers who test drove new cars each day for a sample of 20 days at the Redfield Ford Dealership. 5 7 2 9 4 9 7 10 4 7 5 6 4 0 7 6 3 4 14 6 Given these data, what is the interquartile range? A) 3 B) 7 C) 4 D) 14

Q: The following data reflect the number of customers who test drove new cars each day for a sample of 20 days at the Redfield Ford Dealership. 5 7 2 9 4 9 7 10 4 7 5 6 4 0 7 6 3 4 14 6 Given these data, what is the variance? A) 0.69 B) Approximately 3.08 C) Approximately 9.52 D) Approximately 181

Q: The following data reflect the number of customers who test drove new cars each day for a sample of 20 days at the Redfield Ford Dealership. 5 7 2 9 4 9 7 10 4 7 5 6 4 0 7 6 3 4 14 6 Given these data, what is the range? A) 14 B) 1 C) Approximately 3.08 D) 5.95

Q: Which of the following measures is not affected by extreme values in the data? A) The mean B) The median C) The range D) The standard deviation

Q: Which of the following is the most frequently used measure of variation? A) The range B) The standard deviation C) The variance D) The mode

Q: For ordinal data, ________ is the preferred measure of central location. A) the mean B) the median C) the percentile D) the quartile

Q: The box and whisker plot CANNOT be used to identify: A) skewedness. B) centerness. C) outliers. D) symmetry.