Solutions Essentials of Modern Business Statistics with Microsoft Office Excel - 7th Edition - Chapter 9

9.1 The manager of the Danvers-Hilton Resort Hotel stated that the mean guest bill for a weekend is $600 or less. A member of the hotel’s accounting staff noticed that the total charges for guest bills have been increasing in recent months. The accountant will use a sample of future weekend guest bills to test the manager’s claim.
a. Which form of the hypotheses should be used to test the manager’s claim? Explain....
b. What conclusion is appropriate when H0 cannot be rejected?
c. What conclusion is appropriate when H0 can be rejected?

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9.2 The manager of an automobile dealership is considering a new bonus plan designed to increase sales volume. Currently, the mean sales volume is 14 automobiles per month. The manager wants to conduct a research study to see whether the new bonus plan increases sales volume. To collect data on the plan, a sample of sales personnel will be allowed to sell under the new bonus plan for a one-month period.
a. Develop the null and alternative hypotheses most appropriate for this situation.
b. Comment on the conclusion when H0 cannot be rejected.
c. Comment on the conclusion when H0 can be rejected.

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9.3 A production line operation is designed to fill cartons with laundry detergent to a mean weight of 32 ounces. A sample of cartons is periodically selected and weighed to determine whether underfilling or overfilling is occurring. If the sample data lead to a conclusion of underfilling or overfilling, the production line will be shut down and adjusted to obtain proper filling.
a. Formulate the null and alternative hypotheses that will help in deciding whether to shut down and adjust the production line.
b. Comment on the conclusion and the decision when H0 cannot be rejected.
c. Comment on the conclusion and the decision when H0 can be rejected.

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9.4 Because of high production-changeover time and costs, a director of manufacturing must convince management that a proposed manufacturing method reduces costs before the new method can be implemented. The current production method operates with a mean cost of $220 per hour. A research study will measure the cost of the new method over a sample production period.
a. Develop the null and alternative hypotheses most appropriate for this study.
b. Comment on the conclusion when H0 cannot be rejected.
c. Comment on the conclusion when H0 can be rejected.

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9.5 Duke Energy reported that the cost of electricity for an efficient home in a particular neighborhood of Cincinnati, Ohio, was $104 per month (Home Energy Report, Duke Energy, March 2012). A researcher believes that the cost of electricity for a comparable neighborhood in Chicago, Illinois, is higher. A sample of homes in this Chicago neighborhood will be taken and the sample mean monthly cost of electricity will be used to test the following null and alternative hypotheses....
a. Assume the sample data lead to rejection of the null hypothesis. What would be your conclusion about the cost of electricity in the Chicago neighborhood?
b. What is the Type I error in this situation? What are the consequences of making this error?
c. What is the Type II error in this situation? What are the consequences of making this error?

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9.6 The label on a 3-quart container of orange juice states that the orange juice contains an average of 1 gram of fat or less. Answer the following questions for a hypothesis test that could be used to test the claim on the label.
a. Develop the appropriate null and alternative hypotheses.
b. What is the Type I error in this situation? What are the consequences of making this error?
c. What is the Type II error in this situation? What are the consequences of making this error?

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9.7 Carpetland salespersons average $8000 per week in sales. Steve Contois, the firm’s vice president, proposes a compensation plan with new selling incentives. Steve hopes that the results of a trial selling period will enable him to conclude that the compensation plan increases the average sales per salesperson.
a. Develop the appropriate null and alternative hypotheses.
b. What is the Type I error in this situation? What are the consequences of making this error?
c. What is the Type II error in this situation? What are the consequences of making this error?

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9.8 Suppose a new production method will be implemented if a hypothesis test supports the conclusion that the new method reduces the mean operating cost per hour.
a. State the appropriate null and alternative hypotheses if the mean cost for the current production method is $220 per hour.
b. What is the Type I error in this situation? What are the consequences of making this error?
c. What is the Type II error in this situation? What are the consequences of making this error?

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9.9 Consider the following hypothesis test:...A sample of 50 provided a sample mean of 19.4. The population standard deviation is 2.
a. Compute the value of the test statistic.
b. What is the p-value?
c. Using α = .05, what is your conclusion?
d. What is the rejection rule using the critical value? What is your conclusion?

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9.10 Consider the following hypothesis test:...A sample of 40 provided a sample mean of 26.4. The population standard deviation is 6.
a. Compute the value of the test statistic.
b. What is the p-value?
c. At α = .01, what is your conclusion?
d. What is the rejection rule using the critical value? What is your conclusion?

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9.11 Consider the following hypothesis test:...A sample of 50 provided a sample mean of 14.15. The population standard deviation is 3.
a. Compute the value of the test statistic.
b. What is the p-value?
c. At α= .05, what is your conclusion?
d. What is the rejection rule using the critical value? What is your conclusion?

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9.12 Consider the following hypothesis test:...A sample of 100 is used and the population standard deviation is 12. Compute the p-value and state your conclusion for each of the following sample results. Use α = .01.
a. ...
b. ...
c. ...
d. ...

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9.13 Consider the following hypothesis test:...A sample of 60 is used and the population standard deviation is 8. Use the critical value approach to state your conclusion for each of the following sample results. Use α = .05.
a. ...
b. ...
c. ...

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9.14 Consider the following hypothesis test:...A sample of 75 is used and the population standard deviation is 10. Compute the p-value and state your conclusion for each of the following sample results. Use α = .01.
a. ...
b. ...
c. ...

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9.15 Individuals filing federal income tax returns prior to March 31 received an average refund of $1056. Consider the population of “last-minute” filers who mail their tax return during the last five days of the income tax period (typically April 10 to April 15).
a. A researcher suggests that a reason individuals wait until the last five days is that on average these individuals receive lower refunds than do early filers. Develop appropriate hypotheses such that rejection of H0 will support the researcher’s contention.
b. For a sample of 400 individuals who filed a tax return between April 10 and 15, the sample mean refund was $910. Based on prior experience, a population standard deviation of σ = $1600 may be assumed. What is the p-value?
c. At α = .05, what is your conclusion?
d. Repeat the preceding hypothesis test using the critical value approach.

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9.16 In a study entitled How Undergraduate Students Use Credit Cards, it was reported that undergraduate students have a mean credit card balance of $3173 (Sallie Mae, April 2009). This figure was an all-time high and had increased 44% over the previous five years. Assume that a current study is being conducted to determine if it can be concluded that the mean credit card balance for undergraduate students has continued to increase compared to the April 2009 report. Based on previous studies, use a population standard deviation σ = $1000.
a. State the null and alternative hypotheses.
b. What is the p-value for a sample of 180 undergraduate students with a sample mean credit card balance of $3325?
c. Using a .05 level of significance, what is your conclusion?

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9.17 The mean hourly wage for employees in goods-producing industries is currently $24.57 (Bureau of Labor Statistics website, April, 12, 2012). Suppose we take a sample of employees from the manufacturing industry to see if the mean hourly wage differs from the reported mean of $24.57 for the goods-producing industries.
a. State the null and alternative hypotheses we should use to test whether the population mean hourly wage in the manufacturing industry differs from the population mean hourly wage in the goods-producing industries.
b. Suppose a sample of 30 employees from the manufacturing industry showed a sample mean of $23.89 per hour. Assume a population standard deviation of $2.40 per hour and compute the p-value.
c. With α =.05 as the level of significance, what is your conclusion?
d. Repeat the preceding hypothesis test using the critical value approach.

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9.18 Young millennials, adults aged 18 to 34, are viewed as the future of the restaurant industry. During 2011, this group consumed a mean of 192 restaurant meals per person (NPD Group website, November 7, 2012). Conduct a hypothesis test to determine if the poor economy caused a change in the frequency of consuming restaurant meals by young millennials in 2012.
a. Formulate hypotheses that can be used to determine whether the annual mean number of restaurant meals per person has changed for young millennials in 2012.
b. Based on a sample, the NPD Group stated that the mean number of restaurant meals consumed by young millennials in 2012 was 182. Assume the sample size was 150 and that, based on past studies, the population standard deviation can be assumed to be σ = 55. Use the sample results to compute the test statistic and p-value for your hypothesis test.
c. At α = .05, what is your conclusion?

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9.19 The Internal Revenue Service (IRS) provides a toll-free help line for taxpayers to call in and get answers to questions as they prepare their tax returns. In recent years, the IRS has been inundated with taxpayer calls and has redesigned its phone service as well as posting answers to frequently asked questions on its website (The Cincinnati Enquirer, January 7, 2010). According to a report by a taxpayer advocate, callers using the new system can expect to wait on hold for an unreasonably long time of 12 minutes before being able to talk to an IRS employee. Suppose you select a sample of 50 callers after the new phone service has been implemented; the sample results show a mean waiting time of 10 minutes before an IRS employee comes on line. Based upon data from past years, you decide it is reasonable to assume that the standard deviation of waiting times is 8 minutes. Using your sample results, can you conclude that the actual mean waiting time turned out to be significantly less than the 12-minute claim made by the taxpayer advocate? Use α = .05.
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9.20
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9.21 Fowle Marketing Research, Inc., bases charges to a client on the assumption that telephone surveys can be completed in a mean time of 15 minutes or less. If a longer mean survey time is necessary, a premium rate is charged. A sample of 35 surveys provided the survey times shown in the WEBfile named Fowle. Based upon past studies, the population standard deviation is assumed known with σ = 4 minutes. Is the premium rate justified?
a. Formulate the null and alternative hypotheses for this application.
b. Compute the value of the test statistic.
c. What is the p-value?
d. At α = .01, what is your conclusion?

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9.22 CCN and ActMedia provided a television channel targeted to individuals waiting in supermarket checkout lines. The channel showed news, short features, and advertisements. The length of the program was based on the assumption that the population mean time a shopper stands in a supermarket checkout line is 8 minutes. A sample of actual waiting times will be used to test this assumption and determine whether actual mean waiting time differs from this standard.
a. Formulate the hypotheses for this application.
b. A sample of 120 shoppers showed a sample mean waiting time of 8.4 minutes. Assume a population standard deviation of σ = 3.2 minutes. What is the p-value?
c. At α = .05, what is your conclusion?
d. Compute a 95% confidence interval for the population mean. Does it support your conclusion?

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9.23 Consider the following hypothesis test:...A sample of 25 provided a sample mean ... and a sample standard deviation s = 4.32.
a. Compute the value of the test statistic.
b. use the t distribution table (Table 2 in Appendix B) to compute a range for the p-value.
c. At α = .05, what is your conclusion?
d. what is the rejection rule using the critical value? what is your conclusion?

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9.24 Consider the following hypothesis test:...A sample of 48 provided a sample mean ... and a sample standard deviation s = 4.5.
a. Compute the value of the test statistic.
b. use the t distribution table (Table 2 in Appendix B) to compute a range for the p-value.
c. At α = .05, what is your conclusion?
d. what is the rejection rule using the critical value? what is your conclusion?

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9.25 Consider the following hypothesis test:...A sample of 36 is used. Identify the p-value and state your conclusion for each of the following sample results. Use α = .01.
a. ...
b. ...
c. ...

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9.26 Consider the following hypothesis test:...A sample of 65 is used. Identify the p-value and state your conclusion for each of the following sample results. Use α = .05.
a. ...
b. ...
c. ...

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9.27 Which is cheaper: eating out or dining in? The mean cost of a flank steak, broccoli, and rice bought at the grocery store is $13.04 (Money.msn website, November 7, 2012). A sample of 100 neighborhood restaurants showed a mean price of $12.75 and a standard deviation of $2 for a comparable restaurant meal.
a. Develop appropriate hypotheses for a test to determine whether the sample data support the conclusion that the mean cost of a restaurant meal is less than fixing a comparable meal at home.
b. Using the sample from the 100 restaurants, what is the p-value?
c. At α = .05, what is your conclusion?
d. Repeat the preceding hypothesis test using the critical value approach.

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9.28 A shareholders’ group, in lodging a protest, claimed that the mean tenure for a chief executive officer (CEO) was at least nine years. A survey of companies reported in The Wall Street Journal found a sample mean tenure of ... years for CEOs with a standard deviation of s = 6.38 years (The Wall Street Journal, January 2, 2007).
a. Formulate hypotheses that can be used to challenge the validity of the claim made by the shareholders’ group.
b. Assume 85 companies were included in the sample. what is the p-value for your hypothesis test?
c. At α = .01, what is your conclusion?

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9.29 The national mean annual salary for a school administrator is $90,000 a year (The Cincinnati Enquirer, April 7, 2012). A school official took a sample of 25 school administrators in the state of Ohio to learn about salaries in that state to see if they differed from the national average.
a. Formulate hypotheses that can be used to determine whether the population mean annual administrator salary in Ohio differs from the national mean of $90,000.
b. The sample data for 25 Ohio administrators is contained in the WEBfile named Administrator. what is the p-value for your hypothesis test in part (a)?
c. At α = .05, can your null hypothesis be rejected? What is your conclusion?
d. Repeat the preceding hypothesis test using the critical value approach.

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9.30 The time married men with children spend on child care averages 6.4 hours per week (Time, March 12, 2012). You belong to a professional group on family practices that would like to do its own study to determine if the time married men in your area spend on child care per week differs from the reported mean of 6.4 hours per week. A sample of 40 married couples will be used with the data collected showing the hours per week the husband spends on child care. The sample data are contained in the WEBfile named ChildCare.
a. What are the hypotheses if your group would like to determine if the population mean number of hours married men are spending in child care differs from the mean reported by Time in your area?
b. What is the sample mean and the p-value?
c. Select your own level of significance. What is your conclusion?

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9.31
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9.32 According to the National Automobile Dealers Association, the mean price for used cars is $10,192. A manager of a Kansas City used car dealership reviewed a sample of 50 recent used car sales at the dealership in an attempt to determine whether the population mean price for used cars at this particular dealership differed from the national mean. The prices for the sample of 50 cars are shown in the WEBfile named UsedCars.
a. Formulate the hypotheses that can be used to determine whether a difference exists in the mean price for used cars at the dealership.
b. What is the p-value?
c. At α = .05, what is your conclusion?

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9.33 The mean annual premium for automobile insurance in the United States is $1503 (Insure.com website, March 6, 2014). Being from Pennsylvania, you believe automobile insurance is cheaper there and wish to develop statistical support for your opinion. A sample of 25 automobile insurance policies from the state of Pennsylvania showed a mean annual premium of $1440 with a standard deviation of s = $165.
a. Develop a hypothesis test that can be used to determine whether the mean annual premium in Pennsylvania is lower than the national mean annual premium.
b. What is a point estimate of the difference between the mean annual premium in Pennsylvania and the national mean?
c. At α = .05, test for a significant difference. What is your conclusion?

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9.34 Joan’s Nursery specializes in custom-designed landscaping for residential areas. The estimated labor cost associated with a particular landscaping proposal is based on the number of plantings of trees, shrubs, and so on to be used for the project. For cost-estimating purposes, managers use two hours of labor time for the planting of a medium-sized tree. Actual times from a sample of 10 plantings during the past month follow (times in hours)....With a .05 level of significance, test to see whether the mean tree-planting time differs from two hours.
a. State the null and alternative hypotheses.
b. Compute the sample mean.
c. Compute the sample standard deviation.
d. What is the p-value?
e. What is your conclusion?

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9.35 Consider the following hypothesis test:...A sample of 400 provided a sample proportion ...
a. Compute the value of the test statistic.
b. What is the p-value?
c. At α = .05, what is your conclusion?
d. What is the rejection rule using the critical value? What is your conclusion?

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9.36 Consider the following hypothesis test:...A sample of 300 items was selected. Compute the p-value and state your conclusion for each of the following sample results. Use α = .05.
a. ...
b. ...
c. ...
d. ...

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9.37
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9.38 A study by Consumer Reports showed that 64% of supermarket shoppers believe supermarket brands to be as good as national name brands. To investigate whether this result applies to its own product, the manufacturer of a national name-brand ketchup asked a sample of shoppers whether they believed that supermarket ketchup was as good as the national brand ketchup.
a. Formulate the hypotheses that could be used to determine whether the percentage of supermarket shoppers who believe that the supermarket ketchup was as good as the national brand ketchup differed from 64%.
b. If a sample of 100 shoppers showed 52 stating that the supermarket brand was as good as the national brand, what is the p-value?
c. At α = .05, what is your conclusion?
d. Should the national brand ketchup manufacturer be pleased with this conclusion? Explain.

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9.39 What percentage of the population live in their state of birth? According to the U.S. Census Bureau’s American Community Survey, the figure ranges from 25% in Nevada to 78.7% in Louisiana (AARP Bulletin, March 2014). The average percentage across all states and the District of Columbia is 57.7%. The data in the WEBfile Homestate are consistent with the findings in the American Community Survey. The data are for a random sample of 120 Arkansas residents and for a random sample of 180 Virginia residents.
a. Formulate hypotheses that can be used to determine whether the percentage of stay-at-home residents in the two states differs from the overall average of 57.7%.
b. Estimate the proportion of stay-at-home residents in Arkansas. Does this proportion differ significantly from the mean proportion for all states? Use α = .05.
c. Estimate the proportion of stay-at-home residents in virginia. Does this proportion differ significantly from the mean proportion for all states? Use α = .05.
d. Would you expect the proportion of stay-at-home residents to be higher in Virginia than in Arkansas? Support your conclusion with the results obtained in parts (b) and (c).

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9.40
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9.41 Ten years ago 53% of American families owned stocks or stock funds. Sample data collected by the Investment Company Institute indicate that the percentage is now 46% (The Wall Street Journal, October 5, 2012).
a. Develop appropriate hypotheses such that rejection of H0 will support the conclusion that a smaller proportion of American families own stocks or stock funds in 2012 than 10 years ago.
b. Assume the Investment Company Institute sampled 300 American families to estimate that the percent owning stocks or stock funds was 46% in 2012. what is the p-value for your hypothesis test?
c. At α = .01, what is your conclusion?

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9.42 According to the University of Nevada Center for Logistics Management, 6% of all merchandise sold in the United States gets returned (BusinessWeek, January 15, 2007). A Houston department store sampled 80 items sold in January and found that 12 of the items were returned.
a. Construct a point estimate of the proportion of items returned for the population of sales transactions at the Houston store.
b. Construct a 95% confidence interval for the porportion of returns at the Houston store.
c. Is the proportion of returns at the Houston store significantly different from the returns for the nation as a whole? Provide statistical support for your answer.

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9.43 Eagle Outfitters is a chain of stores specializing in outdoor apparel and camping gear. It is considering a promotion that involves mailing discount coupons to all its credit card customers. This promotion will be considered a success if more than 10% of those receiving the coupons use them. Before going national with the promotion, coupons were sent to a sample of 100 credit card customers.
a. Develop hypotheses that can be used to test whether the population proportion of those who will use the coupons is sufficient to go national.
b. The WEBfile named Eagle contains the sample data. Develop a point estimate of the population proportion.
c. Use α = .05 to conduct your hypothesis test. Should Eagle go national with the promotion?

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9.44 One of the reasons health care costs have been rising rapidly in recent years is the increasing cost of malpractice insurance for physicians. Also, fear of being sued causes doctors to run more precautionary tests (possibly unnecessary) just to make sure they are not guilty of missing something (Reader’s Digest, October 2012). These precautionary tests also add to health care costs. Data in the WEBfile named LawSuit are consistent with findings in the Reader’s Digest article and can be used to estimate the proportion of physicians over the age of 55 who have been sued at least once.
a. Formulate hypotheses that can be used to see if these data can support a finding that more than half of physicians over the age of 55 have been sued at least once.
b. Use Excel and the WEBfile named LawSuit to compute the sample proportion of physicians over the age of 55 who have been sued at least once. what is the p-value for your hypothesis test?
c. At α = .01, what is your conclusion?

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9.45 The American Association of Individual Investors conducts a weekly survey of its members to measure the percent who are bullish, bearish, and neutral on the stock market for the next six months. For the week ending November 7, 2012, the survey results showed 38.5% bullish, 21.6% neutral, and 39.9% bearish (AAII website, November 12, 2012). Assume these results are based on a sample of 300 AAII members.
a. Over the long term, the proportion of bullish AAII members is .39. Conduct a hypothesis test at the 5% level of significance to see if the current sample results show that bullish sentiment differs from its long term average of .39. what are your findings?
b. Over the long term, the proportion of bearish AAII members is .30. Conduct a hypothesis test at the 1% level of significance to see if the current sample results show that bearish sentiment is above its long term average of .30. what are your findings?
c. would you feel comfortable extending these results to all investors? why or why not?

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9.46
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9.47
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9.48
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9.49
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9.50 A production line operates with a mean filling weight of 16 ounces per container. Overfilling or underfilling presents a serious problem and when detected requires the operator to shut down the production line to readjust the filling mechanism. From past data, a population standard deviation σ = .8 ounces is assumed. A quality control inspector selects a sample of 30 items every hour and at that time makes the decision of whether to shut down the line for readjustment. The level of significance is α =.05.
a. State the hypothesis test for this quality control application.
b. If a sample mean of ... ounces were found, what is the p-value? What action would you recommend?
c. If a sample mean of ... ounces were found, what is the p-value? What action would you recommend?
d. Use the critical value approach. What is the rejection rule for the preceding hypothesis testing procedure? Repeat parts (b) and (c). Do you reach the same conclusion?

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9.51 At Western University the historical mean of scholarship examination scores for freshman applications is 900. A historical population standard deviation σ = 180 is assumed known. Each year, the assistant dean uses a sample of applications to determine whether the mean examination score for the new freshman applications has changed.
a. State the hypotheses.
b. What is the 95% confidence interval estimate of the population mean examination score if a sample of 200 applications provided a sample mean of ...?
c. Use the confidence interval to conduct a hypothesis test. Using α =.05, what is your conclusion?
d. What is the p-value?

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9.52 Young children in the United States are exposed to an average of 4 hours of background television per day (CNN website, November 13, 2012). Having the television on in the background while children are doing other activities may have adverse consequences on a child’s wellbeing. You have a research hypothesis that children from low-income families are exposed to more than 4 hours of daily background television. In order to test this hypothesis, you have collected a random sample of 60 children from low-income families and found that these children were exposed to a sample mean of 4.5 hours of daily background television.
a. Develop hypotheses that can be used to test your research hypothesis.
b. Based on a previous study, you are willing to assume that the population standard deviation is σ = 0.5 hours. What is the p-value based on your sample of 60 children from low-income families?
c. Use α =.01 as the level of significance. What is your conclusion?

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9.53 The Wall Street Journal reported that bachelor’s degree recipients with majors in business received average starting salaries of $53,900 in 2012 (The Wall Street Journal, March 17, 2014). The results for a sample of 100 business majors receiving a bachelor’s degree in 2013 showed a mean starting salary of $55,144 with a sample standard deviation of $5200. Conduct a hypothesis test to determine whether the mean starting salary for business majors in 2013 is greater than the mean starting salary in 2012. Use α =.01 as the level of significance.
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9.54
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9.55
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9.56 The chamber of commerce of a Florida Gulf Coast community advertises that area residential property is available at a mean cost of $125,000 or less per lot. Suppose a sample of 32 properties provided a sample mean of $130,000 per lot and a sample standard deviation of $12,500. Use a .05 level of significance to test the validity of the advertising claim.
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9.57 In Hamilton County, Ohio, the mean number of days needed to sell a house is 86 days (Cincinnati Multiple Listing Service, April, 2012). Data for the sale of 40 houses in a nearby county showed a sample mean of 80 days with a sample standard deviation of 20 days. Conduct a hypothesis test to determine whether the mean number of days until a house is sold is different than the Hamilton County mean of 86 days in the nearby county. Use α = .05 for the level of significance, and state your conclusion.
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9.60 Members of the millennial generation are continuing to be dependent on their parents (either living with or otherwise receiving support from parents) into early adulthood (The Enquirer, March 16, 2014). A family research organization has claimed that, in past generations, no more than 30% of individuals aged 18 to 32 continued to be dependent on their parents. Suppose that a sample of 400 individuals aged 18 to 32 showed that 136 of them continue to be dependent on their parents.
a. Develop hypotheses for a test to determine whether the proportion of millennials continuing to be dependent on their parents is higher than for past generations.
b. what is your point estimate of the proportion of millennials that are continuing to be dependent on their parents?
c. What is the p-value provided by the sample data?
d. What is your hypothesis testing conclusion? Use α = .05 as the level of significance.

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9.61 The unemployment rate for 18-to 34-year-olds was reported to be 10.8% (The Cincinnati Enquirer, November 6, 2012). Assume that this report was based on a random sample of four hundred 18-to 34-year-olds.
a. A political campaign manager wants to know if the sample results can be used to conclude that the unemployment rate for 18-to 34-years-olds is significantly higher than the unemployment rate for all adults. According to the Bureau of Labor Statistics, the unemployment rate for all adults was 7.9%. Develop a hypothesis test that can be used to see if the conclusion that the unemployment rate is higher for 18-to 34-year-olds can be supported.
b. Use the sample data collected for the 18-to 34-year-olds to compute the p-value for the hypothesis test in part (a). Using α = .05, what is your conclusion?
c. Explain to the campaign manager what can be said about the observed level of significance for the hypothesis testing results using the p-value.

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9.62 A radio station in Myrtle Beach announced that at least 90% of the hotels and motels would be full for the Memorial Day weekend. The station advised listeners to make reservations in advance if they planned to be in the resort over the weekend. On Saturday night a sample of 58 hotels and motels showed 49 with a no-vacancy sign and 9 with vacancies. What is your reaction to the radio station’s claim after seeing the sample evidence? Use α = .05 in making the statistical test. What is the p-value?
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9.63 In recent years more people have been working past the age of 65. In 2005, 27% of people aged 65–69 worked. A recent report from the Organization for Economic Co-operation and Development (OECD) claimed that the percentage working had increased (USA Today, November 16, 2012). The findings reported by the OECD were consistent with taking a sample of 600 people aged 65–69 and finding that 180 of them were working.
a. Develop a point estimate of the proportion of people aged 65–69 who are working.
b. Set up a hypothesis test so that the rejection of H0 will allow you to conclude that the proportion of people aged 65–69 working has increased from 2005.
c. Conduct your hypothesis test using α = .05. What is your conclusion?

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