Q&A Hero

Q: A random sample of 81 students at a local university showed that they work an average of 100 hours per month. The population standard deviation is known to be 27 hours. Compute a 95% confidence interval for the mean hours per month all students at the university work.

Q: A simple random sample of 144 items resulted in a sample mean of 1080. The population standard deviation is known to be 240. Develop a 95% confidence interval for the population mean.

Q: A random sample of 49 lunch customers was taken at a restaurant. The average amount of time the customers in the sample stayed in the restaurant was 33 minutes. From past experience, it is known that the population standard deviation equals 10 minutes.a. Compute the standard error of the mean.b. What can be said about the sampling distribution for the average amount of time customers spent in the restaurant? Be sure to explain your answer.c. With a .95 probability, what statement can be made about the size of the margin of error?d. Construct a 95% confidence interval for the true average amount of time customers spent in the restaurant.e. With a .95 probability, how large of a sample would have to be taken to provide a margin of error of 2.5 minutes or less?

Q: A random sample of 121 checking accounts at a bank showed an average daily balance of $280. The population standard deviation is known to be $60.a. Is it necessary to know anything about the shape of the distribution of the account balances in order to make an interval estimate of the mean of all the account balances? Explain.b. Find the standard error of the mean.c. Give a point estimate of the population mean.d. Construct a 95% confidence interval estimate for the population mean.e. Interpret the confidence interval estimate that you constructed in part d.

Q: A small stock brokerage firm wants to determine the average daily sales (in dollars) of stocks to their clients. A sample of the sales for 36 days revealed average daily sales of $200,000. Assume that the standard deviation of the population is known to be $18,000.a. Provide a 95% confidence interval estimate for the average daily sale.b. Provide a 97% confidence interval estimate for the average daily sale.

Q: In order to determine the average weight of carry-on luggage by passengers in airplanes, a sample of 36 pieces of carry-on luggage was weighed. The average weight was 20 pounds. Assume that we know the standard deviation of the population to be 8 pounds.a. Determine a 97% confidence interval estimate for the mean weight of the carry-on luggage.b. Determine a 95% confidence interval estimate for the mean weight of the carry-on luggage.

Q: A random sample of 100 credit sales in a department store showed an average sale of $120.00. From past data, it is known that the standard deviation of the population is $40.00.a. Determine the standard error of the mean.b. With a 0.95 probability, determine the margin of error.c. What is the 95% confidence interval of the population mean?

Q: In order to estimate the average electric usage per month, a sample of 196 houses was selected and the electric usage determined.a. Assume a population standard deviation of 350 kilowatt hours. Determine the standard error of the mean.b. With a 0.95 probability, determine the margin of error.c. If the sample mean is 2,000 KWH, what is the 95% confidence interval estimate of the population mean?

Q: X is a exponentially distributed random variable with a mean of 10. Use Excel to calculate the following:

Q: The time it takes to completely tune an engine of an automobile follows an exponential distribution with a mean of 40 minutes.a. Define the random variable in words.b. What is the probability of tuning an engine in 30 minutes or less?c. What is the probability of tuning an engine between 30 and 35 minutes?

Q: The time required to assemble a part of a machine follows an exponential probability distribution with a mean of 14 minutes.a. What is the probability that the part can be assembled in 7 minutes or less?b. What is the probability that the part can be assembled between 3.5 and 7 minutes?

Q: The time between arrivals of customers at the drive-up window of a bank follows an exponential probability distribution with a mean of 10 minutes.a. What is the probability that the arrival time between customers will be 7 minutes or less?b. What is the probability that the arrival time between customers will be between 3 and 7 minutes?

Q: The time it takes a worker on an assembly line to complete a task is exponentially distributed with a mean of 8 minutes.a. What is the probability density function for the time it takes to complete the task?b. What is the probability that it will take a worker less than 4 minutes to complete the task?c. What is the probability that it will take a worker between 6 and 10 minutes to complete the task?

Q: The time it takes a mechanic to change the oil in a car is exponentially distributed with a mean of 5 minutes.a. What is the probability density function for the time it takes to change the oil?b. What is the probability that it will take a mechanic less than 6 minutes to change the oil?c. What is the probability that it will take a mechanic between 3 and 5 minutes to change the oil?

Q: X is a normally distributed random variable with a mean of 50 and a standard deviation of 5. Use Excel to calculate the following:

Q: Z is the standard normal random variable. Use Excel to calculate the following:

Q: A manufacturing process produces items whose weights are normally distributed. It is known that 22.57% of all the items produced weigh between 100 grams up to the mean and 49.18% weigh from the mean up to 190 grams. Determine the mean and the standard deviation.

Q: In grading eggs into small, medium, and large, the Linda Farms packs the eggs that weigh more than 3.6 ounces in packages marked "large" and the eggs that weigh less than 2.4 ounces into packages marked "small"; the remainder are packed in packages marked "medium." If a day's packaging contained 10.2% large and 4.18% small eggs, determine the mean and the standard deviation for the eggs' weights. Assume that the distribution of the weights is normal.

Q: The Globe Fishery packs shrimp that weigh more than 1.91 ounces each in packages marked" large" and shrimp that weigh less than 0.47 ounces each into packages marked "small"; the remainder are packed in "medium" size packages. If a day's catch showed that 19.77% of the shrimp were large and 6.06% were small, determine the mean and the standard deviation for the shrimp weights. Assume that the shrimps' weights are normally distributed.

Q: The monthly earnings of computer programmers are normally distributed with a mean of $4,000. If only 1.7 percent of programmers have monthly incomes of less than $2,834, what is the value of the standard deviation of the monthly earnings of the computer programmers?

Q: The weekly earnings of bus drivers are normally distributed with a mean of $395. If only 1.1% of the bus drivers have a weekly income of more than $429.35, what is the value of the standard deviation of the weekly earnings of the bus drivers?

Q: A local bank has determined that the daily balances of the checking accounts of its customers are normally distributed with an average of $280 and a standard deviation of $20.a. What percentage of its customers has daily balances of more than $275?b. What percentage of its customers has daily balances less than $243?c. What percentage of its customers' balances is between $241 and $301.60?

Q: The average starting salary of this year's MBA students is $35,000 with a standard deviation of $5,000. Furthermore, it is known that the starting salaries are normally distributed. What are the minimum and the maximum starting salaries of the middle 95% of MBA graduates?

Q: The monthly income of residents of Daisy City is normally distributed with a mean of $3000 and a standard deviation of $500.a. Define the random variable in words.b. The mayor of Daisy City makes $2,250 a month. What percentage of Daisy City's residents has incomes that are more than the mayor's?c. Individuals with incomes of less than $1,985 per month are exempt from city taxes. What percentage of residents is exempt from city taxes?d. What are the minimum and the maximum incomes of the middle 95% of the residents?e. Two hundred residents have incomes of at least $4,440 per month. What is the population of Daisy City?

Q: The daily dinner bills in a local restaurant are normally distributed with a mean of $28 and a standard deviation of $6.a. Define the random variable in words.b. What is the probability that a randomly selected bill will be at least $39.10?c. What percentage of the bills will be less than $16.90?d. What are the minimum and maximum of the middle 95% of the bills?e. If twelve of one day's bills had a value of at least $43.06, how many bills did the restaurant collect on that day?

Q: DRUGS R US" is a large manufacturer of various kinds of liquid vitamins. The quality control department has noted that the bottles of vitamins marked 6 ounces vary in content with a standard deviation of 0.3 ounces. Assume the contents of the bottles are normally distributed.a. What percentage of all bottles produced contains more than 6.51 ounces of vitamins?b. What percentage of all bottles produced contains less than 5.415 ounces?c. What percentage of bottles produced contains between 5.46 and 6.495 ounces?d. Ninety-five percent of the bottles will contain at least how many ounces?e. What percentage of the bottles contains between 6.3 and 6.6 ounces?

Q: A professor at a local university noted that the grades of her students were normally distributed with a mean of 78 and a standard deviation of 10.a. The professor has informed us that 16.6% of her students received grades of A. What is the minimum score needed to receive a grade of A?b. If 12.1% of her students failed the course and received Fs, what was the maximum score among those who received an F?c. If 33% of the students received grades of B or better (i.e., As and Bs), what is the minimum score of those who received a B?

Q: The weights of the contents of cans of tomato paste produced by a company are normally distributed with a mean of 6 ounces and a standard deviation of 0.3 ounces.a. What percentage of all cans produced contains more than 6.51 ounces of tomato paste?b. What percentage of all cans produced contains less than 5.415 ounces?c. What percentage of cans contains between 5.46 and 6.495 ounces?d. Ninety-five percent of cans will contain at least how many ounces?e. What percentage of cans contains between 6.3 and 6.6 ounces?

Q: The life expectancy of Timely brand watches is normally distributed with a mean of four years and a standard deviation of eight months.a. What is the probability that a randomly selected watch will be in working condition for more than five years?b. The company has a three-year warranty period on their watches. What percentage of their watches will be in operating condition after the warranty period?c. What is the minimum and the maximum life expectancy of the middle 95% of the watches?d. Ninety-five percent of the watches will have a life expectancy of at least how many months?

Q: The weights of items produced by a company are normally distributed with a mean of 4.5 ounces and a standard deviation of 0.3 ounces.a. What is the probability that a randomly selected item from the production will weigh at least 4.14 ounces?b. What percentage of the items weighs between 4.8 and 5.04 ounces?c. Determine the minimum weight of the heaviest 5% of all items produced.d. If 27,875 of the items of the entire production weigh at least 5.01 ounces, how many items have been produced?

Q: The average starting salary for this year's graduates at a large university (LU) is $30,000 with a standard deviation of $8,000. Furthermore, it is known that the starting salaries are normally distributed.a. What is the probability that a randomly selected LU graduate will have a starting salary of at least $30,400?b. Individuals with starting salaries of less than $15,600 receive a low income tax break. What percentage of the graduates will receive the tax break?c. What are the minimum and the maximum starting salaries of the middle 95% of the LU graduates?d. If 303 of the recent graduates have salaries of at least $43,120, how many students graduated this year from this university?

Q: Scores on a recent national statistics exam were normally distributed with a mean of 80 and a standard deviation of 6.a. What is the probability that a randomly selected exam will have a score of at least 71?b. What percentage of exams will have scores between 89 and 92?c. If the top 2.5% of test scores receive merit awards, what is the lowest score eligible for an award?d. If there were 334 exams with scores of at least 89, how many students took the exam?

Q: The life expectancy of computer terminals is normally distributed with a mean of 4 years and a standard deviation of 10 months.a. What is the probability that a randomly selected terminal will last more than 5 years?b. What percentage of terminals will last between 5 and 6 years?c. What percentage of terminals will last less than 4 years?d. What percentage of terminals will last between 2.5 and 4.5 years?e. If the manufacturer guarantees the terminals for 3 years (and will replace them if they malfunction), what percentage of terminals will be replaced?

Q: The contents of soft drink bottles are normally distributed with a mean of twelve ounces and a standard deviation of one ounce.a. What is the probability that a randomly selected bottle will contain more than ten ounces of soft drink?b. What is the probability that a randomly selected bottle will contain between 9.5 and 11 ounces?c. What percentage of the bottles will contain less than 10.5 ounces of soft drink?

Q: The Japanese language teaches people to think in a non-linear mode.

Q: Which of the following topics would be considered a conversation taboo in Mexico? a. history b. family c. politics d. social concerns

Q: Syntactic errors are errors in the content and meaning of words in a sentence.

Q: A good interpreter will be a. bilingual, familiar with both business cultures, and employed by one of the businesses. b. bicultural, bilingual, and familiar with both business cultures. c. bicultural and an employee of the visiting business. d. bicultural, bilingual, and employed by the host business.

Q: French laws prevent age discrimination.

Q: A Group Decision Support System is a a. software package used for group meetings and allows multilingual communication. b. management program for distribution control. c. pocket translator. d. probability package used by managers to determine the best possible decision alternative.

Q: In many countries, the facsimile is more dependable than the mail service.

Q: Which of the following would be an example of a translation problem? a. Using the intention of the speaker rather than the actual words in the translation. b. Qualifying slang terms. c. Not translating conversation taboos. d. Using a word for which no exact word or concept is available in the second language.

Q: Latin Americans avoid negative news completely in their correspondence.

Q: "The part was found defective, and it was determined that there is a defect in the button causing it not to fit into the chassis." This statement is an example of a a. linear explanation. b. verbose explanation. c. nonlinear explanation. d. why explanation.

Q: The Japanese use silence as a bargaining tool when negotiating with persons from the United States.

Q: Another word for gamesmanship would be a. idiom. b. verbal dueling. c. argument. d. repartee.

Q: In the Middle East, eye contact is so intense that it exceeds the comfort zone for people in the United States.

Q: Red tape is an example of a. slang. b. an acronym. c. a homonym. d. an idiom.

Q: People of the United States tend to need less space than do people in Latin America.

Q: Slang is generally a. understood by everyone. b. spoken by the masses. c. easily translated. d. used by subgroups.

Q: Negotiation tactics are concerned with your counterpart's comforts.

Q: The term "jargon" refers to a. inoffensive expressions that are used in place of offensive words. b. competitive conversations that are generally in jest. c. technical terminology used within specialized groups. d. nonverbal signals that are believed over what is actually said.

Q: The cooperative pragmatist is concerned with the outcome for all parties concerned.

Q: Which of the following terms regarding subjective interpretation is incorrect? a. It is influenced by personal judgment, state of mind, or temperament of the person. b. It is not influenced by cultural contact. c. We perceive what is relevant to our physical and social survival. d. Relevant information is categorized, sorted, and stored for future use.

Q: Maintaining ties with the home culture may cushion the shock associated with reentry.

Q: Which of the following countries uses high-context language? a. Canada b. Germany c. Japan d. United States

Q: NAFTA is a trade agreement between the U.S., Mexico, and Canada.

Q: Language is important because it a. helps us shape concepts, controls how we think, and controls how we perceive others. b. allows us to be understood by foreigners. c. is determined by colonialism. d. is stable, easily understood, and free of diversity.

Q: The term sojourners refer to people who visit or reside temporarily in another country.

Q: Bernstein's Hypothesis involves restricted and elaborated codes.

Q: People in the U.S. are less concerned with saving face than are people in Asia.

Q: The primary difference between an argot and a foreign language is the relationship between the implied and the unimplied meanings.

Q: People of Latin cultures do not place as great an emphasis on history as do people of the United States.

Q: Parables and proverbs deal with truths simply and concretely and teach the listener a lesson.

Q: U.S. Americans place great importance on individuality and self-reliance.

Q: Linguistic relativity is the idea of language shaping what people consider to be reality.

Q: People from countries with weak uncertainty avoidance are more likely to remain close friends in spite of differing opinions.

Q: The Sapir-Whorf Hypothesis is associated with linguistic determination.

Q: The Japanese educational system stresses pragmatic thinking.

Q: A conversation taboo in Germany is politics.

Q: Mexicans view social reciprocity as very important.

Q: The Chinese language poses special difficulties when it comes to homonyms.

Q: A nuclear family consists of parents, children, grandparents, aunts, uncles, and cousins.

Q: Linear language is circular, subjective, and tradition oriented.

Q: Cultural synergy takes place when a larger culture breaks apart to form two or more separate cultures.

Q: Subjective interpretation is learned through enculturation.

Q: International business is increasing in the United States.

Q: Low-context languages tend to be very indirect and nonverbal.

Q: Ethnocentric management does not account for cultural differences in the work force.

Q: Learning a second language does not distort or change a person's perspective.