MSIT TEST 3 Ch 14

2. In a metal fabrication process, metal rods are produced to a specified target length of 15 feet. Suppose that the lengths are normally distributed. A quality control specialist collects a random sample of 16 rods and finds the sample mean length to be 14.8 feet and a standard deviation of 0.65 feet. The standard error of the mean is A. 0.65 ft. B. 0.346 ft. C. 0.1625 ft. D. 0.0098 ft. E. 1.625 ft.

C. 0.1625 ft.

7. Which of the following is not an assumption and/or condition required for constructing a confidence interval for the mean? A. Randomization condition B. Nearly Normal condition C. Success/Failure condition D. 10% condition E. Independence assumption

C. Success/Failure condition

4. Vending machines on a college campus offer a variety of snacks. The purchasing agent believes that each type of snack is equally preferred by students and consequently orders equal quantities. The number of snacks sold from vending machines on this campus for the last six months is shown in the following table. The correct value of the test statistic for determining if the purchasing agent's belief if supported is A. χ 2 = 8.012 B. χ 2 = 12.019 C. χ 2 = 0.984 D. χ 2 = 45.014 E. None of the above.

A. χ 2 = 8.012

4. Data were collected on annual personal time (in hours) taken by a random sample of 16 women and 7 men employed by a medium sized company. The women took an average of 24.75 hours of personal time per year with a standard deviation of 2.84 hours. The men took an average of 21.89 hours of personal time per year with a standard deviation of 3.29 hours. The correct 90% confidence interval for the difference between women and men in the average number of hours of personal time taken per year is A. 0.30 to 5.48 hours. B. -0.50 to 3.21 hours. C. -4.67 to -0.62 hours. D. 1.27 to 6.89 hours. E. None of the above.

A. 0.30 to 5.48 hours.

3. A small business ships specialty homemade candies to anywhere in the world. Past records indicate that the weight of orders is normally distributed. Suppose a random sample of 16 orders is selected and each is weighed. The sample mean was found to be 110 grams with a standard deviation of 14 grams. The 90% confidence interval for the true mean weight of orders is A. 103.87 to 116.14 grams. B. 86.046 to 133.954 grams. C. 99.5 to 120.5 grams. D. 102.55 to 117.45 grams. E. 103.14 to 116.86 grams.

A. 103.87 to 116.14 grams.

3. Vending machines on a college campus offer a variety of snacks. The purchasing agent believes that each type of snack is equally preferred by students and consequently orders equal quantities. The number of snacks sold from vending machines on this campus for the last six months is shown in the following table. If the purchasing agent is correct, how many candy bars would we expect to have been sold? A. 170 B. 198 C. 125 D. 180 E. 680

A. 170

4. A manufacturer of cheese filled ravioli supplies a pizza restaurant chain. Based on data collected from its automatic filling process, the amount of cheese inserted = into the ravioli is normally distributed. To make sure that the automatic filling process is on target, quality control inspectors take a sample of 25 ravioli. The correct value of t* to construct a 98% confidence interval for the true mean amount of cheese filling is A. 2.492 B. 3.467 C. 2.797 D. 2.064 E. 3.745

A. 2.492

4. A manufacturer of cream filled donuts collected data from its automatic filling process, the amount of cream inserted into the donuts is normally distributed. To make sure that the automatic filling process is on target, quality control inspectors take a sample of 25 donuts. The correct value of t* to construct a 99% confidence interval for the true mean amount of cream filling is A. 2.797 B. 1.711 C. 2.787 D. 2.060 E. 1.318

A. 2.797

6. Grandma Gertrude's Chocolates, a family owned business, has an opportunity to supply its product for distribution through a large coffee house chain. However, the coffee house chain has certain specifications regarding cacao content as it wishes to advertise the health benefits (antioxidants) of the chocolate products it sells. In order to determine the mean % cacao in its dark chocolate products, quality inspectors sample 36 pieces. They find a sample mean of 55% with a standard deviation of 4%. The 90% confidence interval for the true mean % cacao is A. 53.87% to 56.13%. B. 51% to 59%. C. 53.33% to 56.67%. D. 53.64% to 56.36% E. 54.33% to 55.67%.

A. 53.87% to 56.13%.

8. A manufacturing plant for recreational vehicles receives shipments from three different parts vendors. There has been a defect issue with some of the electrical wiring in the recreational vehicles manufactured at the plant. The plant manager believes that the defect issue is dependent on the parts vendor. The plant manager reviews a sample of quality assurance inspections from the last six months. The expected number of perfect parts from Made-4-U Co. is A. 75.9 B. 91.08 C. 71 D. 61.81 E. 252

A. 75.9

6. Insurance companies track life expectancy information to assist in determining the cost of life insurance policies. ABI Insurance randomly sampled 100 recently paid policies and determined the average age of clients in this sample to be 77.7 years with a standard deviation of 3.6. The 90% confidence interval for the true mean age of its life insurance policy holders is A. 77.1 to 78.3 years B. 76.87 to 80.33 years C. 75.4 to 80 years D. 74.1 to 81.3 years E. 72.5 to 82.9 years

A. 77.1 to 78.3 years

10. A real estate agency, located in a metropolitan area in the northeastern U.S., kept data on the various types of properties purchased in the area. Historically, 15% of purchases were for condominiums, 30% were for townhouses, 40% for single family homes, 10% for commercial properties and 5% for land. Based on the data shown below, the null hypothesis was rejected and the agency concluded that the current distribution of property sales differs from the historical distribution. Based on an examination of the standardized residuals, which type of property had the most impact on the test results? A. Condos B. Townhouses C. Homes D. Commercial E. Land

A. Condos

15T. Chris Columbus is responsible for controlling inventory levels for four types of sailboats sold by his company. Chris takes a sample of 48 boats sold over the past several months to determine if demand is the same for each type. His results are as follows: At the 0.05 level of significance, the correct conclusion is A. Evidence suggests that the demand is the same for different types of boats. B. Evidence suggests that the demand is not the same for different types of boats. C. Reject the null hypothesis. D. Both A and C. E. Both B and C.

A. Evidence suggests that the demand is the same for different types of boats.

6. A real estate agency, located in a metropolitan area in the northeastern U.S., kept data on the various types of properties purchased in the area. Historically, 15% of purchases were for condominiums, 30% were for townhouses, 40% for single family homes, 10% for commercial properties and 5% for land. With changing demographics, the agency wondered if the current distribution matches the historical distribution. Recent data showed the following: Which Chi-square test is most appropriate for this situation? A. Goodness of Fit B. Homogeneity C. Independence D. Proportional E. None of the above.

A. Goodness of Fit

1. A report on the U.S. economy indicates that 28% of Americans have experienced difficulty in making mortgage payments. A news organization randomly sampled 400 Americans from 10 cities named the "fastest dying cities in the U.S." (Forbes Magazine, August 2008) and found that 136 reported such difficulty. Does this indicate that the problem is more severe among these cities? The correct null and alternative hypotheses for testing this claim are A. H0 : p = 0.28 and HA : p > 0.28 B. H0 : p = 0.28 and HA : p < 0.28 C. H0 : p = 0.28 and HA : p ≠ 0.28 D. H0 : p ≠ 0.28 and HA : p = 0.28 E. H0 : p > 0.28 and HA : p = 0.28

A. H0 : p = 0.28 and HA : p > 0.28

6. A pharmaceutical company wants to answer the question whether it takes longer than 45 seconds for a drug in pill form to dissolve in the gastric juices of the stomach. A sample was taken from patients taken the given drug in pill form and times for the pills to be dissolved were measured. State the hypotheses to test this question. A. H0 :μ = 45sec; HA :μ > 45sec B. H : 45sec;H : 45sec 0 A μ > μ ≤ C. H : 45sec;H : 45sec 0 A μ = μ ≤ D. 0 45 45 A H : μ ≥ sec;H : μ < sec E. H : 45sec;H : 45sec

A. H0 :μ = 45sec; HA :μ > 45sec

2. A consumer group was interested in comparing the operating time of cordless toothbrushes manufactured by two different companies. Group members took a random sample of 18 toothbrushes from Company A and 15 from Company B. Each was charged overnight and the number of hours of use before needing to be recharged was recorded. Company A toothbrushes operated for an average of 119.7 hours with a standard deviation of 1.74 hours; Company B toothbrushes operated for an average of 120.6 hours with a standard deviation of 1.72 hours. Do these samples indicate that Company B toothbrushes operate more hours on average than Company A toothbrushes? The correct hypotheses to address this question are A. H0: μA - μB = 0 and HA: μA - μB < 0 B. H0: μA - μB = 0 and HA: μA - μB ≠ 0. C. H0: μA - μB = 0 and HA: μA - μB > 0. D. H0: μA - μB > 0 and HA: μA - μB < 0. E. None of the above.

A. H0: μA - μB = 0 and HA: μA - μB < 0

6T. A professor was interested in determining whether the prices of new textbooks in the bookstore were higher than if purchased online. She selected 6 textbooks and priced each at the bookstore and online. <b>DATA</b> Based on her analysis, we can conclude at the 0.05 level of significance that A. The prices are the same in the bookstore and online. B. The prices are higher in the bookstore. C. The prices are higher online. D. The prices are different in the bookstore and online. E. The analysis is not conclusive.

A. The prices are the same in the bookstore and online.

5. A consumer group was interested in comparing the operating time of cordless toothbrushes manufactured by two different companies. Group members took a random sample of 18 toothbrushes from Company A and 15 from Company B. Each was charged overnight and the number of hours of use before needing to be recharged was recorded. Company A toothbrushes operated for an average of 119.7 hours with a standard deviation of 1.74 hours; Company B toothbrushes operated for an average of 120.6 hours with a standard deviation of 1.72 hours. The 90% confidence interval is (-1.93, 0.13). The correct interpretation is A. We are 90% confident that, on average, there is no difference in operating hours between toothbrushes from Company A compared to those from Company B. B. We are 90% confident that, on average, the toothbrushes from Company A operate longer before needing to be recharged than the toothbrushes from Company B. C. We are 90% confident that, on average, the toothbrushes from Company B operate longer before needing to be recharged than the toothbrushes from Company A. D. We are 90% confident that, on average, there is a difference in operating hours between toothbrushes from Company A compared to those from Company B. E. None of the above.

A. We are 90% confident that, on average, there is no difference in operating hours between toothbrushes from Company A compared to those from Company B.

7. A large software development firm recently relocated its facilities. Top management is interested in fostering good relations with their new local community and has encouraged their professional employees to engage in local service activities. They wish to determine the average number of hours the firm's professionals volunteer per month. They find the 95% confidence interval of 14.62 to 15.78. Which of the following is the correct interpretation? A. We are 95% confident that the average number of hours per month volunteered by professionals employed with this firm is between 14.62 and 15.78. B. 95% of all firm's professional employees volunteer between 14.62 and 15.78 hours per month. C. The number of hours per month volunteered by the firm's professional employees is between 14.62 and 15.78 95% of the time. D. All of the above. E. None of the above.

A. We are 95% confident that the average number of hours per month volunteered by

5. Before being released to market, a drug company tests a new allergy medication for potential side effects. A random sample of 160 individuals with allergies was selected for the study. The new allergy medication was randomly assigned to 80 of them, and another popular allergy medication already on the market (Brand C) was assigned to the rest. Out of the 80 given the new allergy medication, 14 reported drowsiness; 22 of the 80 taking Brand C reported drowsiness. The 95% confidence interval for the difference in proportions reporting drowsiness is -0.028 to 0.228. Which of the following is correct? A. We are 95% confident that there is no difference between the proportions of patients reporting drowsiness for the two allergy medications. B. We are 95% confident that there is a difference between the proportions of patients reporting drowsiness for the two allergy medications. C. We are 95% confident that the proportion of patients reporting drowsiness is higher for the new allergy medication. D. We are 95% confident that the proportion of patients reporting drowsiness is lower for the new allergy medication. E. There will be a significant difference between the proportions 95% of the time.

A. We are 95% confident that there is no difference between the proportions of patients reporting drowsiness for the two allergy medications.

8. A manufacturer of cheese filled ravioli supplies a pizza restaurant chain. Based on data collected from its automatic filling process, the amount of cheese inserted into the ravioli is normally distributed. To make sure that the automatic filling process is on target, quality control inspectors take a sample of 25 ravioli and measure the weight of cheese filling. They find the 99% confidence interval of 4.16 to 15.84 grams. Which of the following is the correct interpretation? A. We are 99% confident that the mean weight of cheese filling in all ravioli made by this process is between 14.16 and 15.84 grams. B. 99% of all ravioli made by this process will have cheese filling weights between 14.16 and 15.84 grams. C. The weight of cheese filling in the ravioli is between 14.16 and 15.84 grams 99% of the time. D. All of the above. E. None of the above.

A. We are 99% confident that the mean weight of cheese filling in all ravioli made by this process is between 14.16 and 15.84 grams.

8. A manufacturer of cream filled donuts collected data from its automatic filling process, the amount of cream inserted into the donuts is normally distributed. To make sure that the automatic filling process is on target, quality control inspectors take a sample of 25 donuts and measure the weight of cream filling. They find the 99% confidence interval of 14.16 to 15.84 grams. Which of the following is the correct interpretation? A. We are 99% confident that the mean weight of cream filling in all donuts made by this process is between 14.16 and 15.84 grams. B. 99% of all donuts made by this process will have cream filling weights between 14.16 and 15.84 grams. C. The weight of cream filling in the donuts is between 14.16 and 15.84 grams 99% of the time. D. All of the above. E. None of the above.

A. We are 99% confident that the mean weight of cream filling in all donuts made by this process is between 14.16 and 15.84 grams.

7. A report on the U.S. economy indicates that 28% of Americans have experienced difficulty in making mortgage payments. A news organization randomly sampled 400 Americans from 10 cities named the "fastest dying cities in the U.S." (Forbes Magazine, August 2008) and found that 136 reported such difficulty. Does this indicate that the problem is more severe among these cities? The P-value associated with the test statistic for testing this claim is 0.0029. At α = .05, A. We can conclude that the percentage of Americans in these cities experiencing difficulty making mortgage payments is significantly higher than 28%. B We can conclude that the percentage of Americans in these cities experiencing difficulty making mortgage payments is significantly lower than 28%. C. We can conclude that the percentage of Americans in these cities experiencing difficulty making mortgage payments is not significantly different from 28%. D. We can conclude that the percentage of Americans in these cities experiencing difficulty making mortgage payments is equal to 28%. E. None of the above.

A. We can conclude that the percentage of Americans in these cities experiencing difficulty making mortgage payments is significantly higher than 28%.

6. An army depot that overhauls ground mobile radar systems is interested in improving its processes. One problem involves troubleshooting a particular component that has a high failure rate after it has been repaired and reinstalled in the system. The shop floor supervisor believes that having standard work procedures in place will reduce the time required for troubleshooting this component. Time (in minutes) required troubleshooting this component without and with the standard work procedure is recorded for a sample of 19 employees. In order to determine if having a standard work procedure in place reduces troubleshooting time, they should use A. a one-tailed paired t-test. B. a two-tailed test of two independent means. C. a one-tailed test of two independent means. D. a two-tailed paired t-test. E. a test of two proportions.

A. a one-tailed paired t-test.

7. A mid-sized company has decided to implement an enterprise resource planning (ERP) system, and management suspects that many of its employees are concerned about the planned implementation. Managers are considering holding informational workshops to help decrease anxiety levels among employees. To determine whether such an approach would be effective, they randomly select 16 employees to participate in a pilot workshop. These employees were given a questionnaire to measure anxiety levels about ERP before and after participating in the workshop. To determine if anxiety levels about ERP decreases as a result of the workshop, they should use a A. one-tailed paired t-test. B. two-tailed test of two independent means. C. one-tailed test of two independent means. D. two-tailed paired t-test. E. one-tailed test of two proportions.

A. one-tailed paired t-test.

3. Results of a small experiment show that people are likely to offer a different amount for used exercise equipment when bargaining with a friend than when bargaining with a stranger. The p-value from testing the difference in mean offers was equal to 0.00162. At an α = 0.05, the correct conclusion is to A. reject the null hypothesis. B. fail to reject the null hypothesis. C. conclude that there is no difference between bargaining with a stranger versus a friend. D. Both A and C. E. Both B and C.

A. reject the null hypothesis.

9. A large software development firm recently relocated its facilities. Top management is interested in fostering good relations with their new local community and has encouraged their professional employees to engage in local service activities. They believe that the firm's professionals volunteer an average of more than 15 hours per month. If this is not the case, they will institute an incentive program to increase community involvement. A random sample of 24 professionals yields a mean of 16.6 hours and a standard deviation of 2.22 hours. The correct value of the test statistic for the appropriate hypothesis test is A. t = 3.532 B. t = -3.532 C. t = 1.223 D. t = -1.223 E. t = 0.789

A. t = 3.532

2. An online department store wants to determine if there is an association between coupon redemption and gender. After a special coupon broadcast to its reward members, the following data on coupon redemption at check out were collected. The correct value of the test statistic is A. χ 2 = 5.339 B. χ 2 = 8.429 C. χ 2 = 0.839 D. χ 2 = 45.556 E. None of the above.

A. χ 2 = 5.339

4. Previous surveys reported that more men than women trade stocks online. A local brokerage firm randomly selected a sample of investors. They found that 45 out of 234 men traded online and 42 out of 251 women traded online. The 95% confidence interval for the difference in proportions is A. 4% to 9% B. -4% to 9% C. 2% to 12% D. -2% to 12% E. -2% to -4%

B. -4% to 9%

5. A manufacturer of cheese filled ravioli supplies a pizza restaurant chain. Based on data collected from its automatic filling process, the amount of cheese inserted into the ravioli is normally distributed. To make sure that the automatic filling process is on target, quality control inspectors take a sample of 25 ravioli and measure the weight of cheese filling. They find a sample mean weight of 15 grams with a standard deviation of 1.5 grams. What is the margin of error at 90% confidence? A. 0.3 grams B. 0.5133 grams C. 0.8391 grams D. 1.5 grams E. 0.06 grams

B. 0.5133 grams

5. A manufacturer of cream filled donuts collected data from its automatic filling process, the amount of cream inserted into the donuts is normally distributed. To make sure that the automatic filling process is on target, quality control inspectors take a sample of 25 donuts and measure the weight of cream filling. They find a sample mean weight of 15 grams with a standard deviation of 1.5 grams. What is the margin of error at 90% confidence? A. 0.3 grams B. 0.5133 grams C. 0.8391 grams D. 1.5 grams E. 0.06 grams

B. 0.5133 grams

14T. Chris Columbus is responsible for controlling inventory levels for four types of sailboats sold by his company. Chris takes a sample of 48 boats sold over the past several months to determine if demand is the same for each type. His results are as follows: The calculated value of the Chi Square statistic is A. 7.815 B. 1.17 C. 22.35 D. -1.17 E. 12.56

B. 1.17

5. Grandma Gertrude's Chocolates, a family owned business, has an opportunity to supply its product for distribution through a large coffee house chain. However, the coffee house chain has certain specifications regarding cacao content as it wishes to advertise the health benefits (antioxidants) of the chocolate products it sells. In order to determine the mean % cacao in its dark chocolate products, quality inspectors sample 36 pieces. They find a sample mean of 55% with a standard deviation of 4%. What is the margin of error at 95% confidence? A. 1.13% B. 1.36% C. 0.67% D. 4% E. 1.67%

B. 1.36%

10. For a one-sided alternative hypothesis, the critical t value for anαof 0.02 and df of 19 is A. 1.734 B. 2.093 C. 2.540 D. 1.729 E. 3.883

B. 2.093

6. Data were collected on annual personal time (in hours) taken by a random sample of 16 women and 20 men employed by a medium-sized company. The women took an average of 24.75 hours of personal time per year with a standard deviation of 2.84 hours. The men took an average of 20.5 hours of personal time per year with a standard deviation of 2.75 hours. If we use the pooled t-test to see if there is a difference between the two groups, the degrees of freedom for the appropriate t-statistic is A. 36 B. 34 C. 20 D. 16 E. None of the above.

B. 34

6. A manufacturing plant for recreational vehicles receives shipments from three different parts vendors. There has been a defect issue with some of the electrical wiring in the recreational vehicles manufactured at the plant. The plant manager believes that the defect issue is dependent on the parts vendor. The plant manager reviews a sample of quality assurance inspections from the last six months. Which Chi-square test is most appropriate for this situation? A. Goodness of Fit B. Homogeneity C. Dependence D. Proportional E. None of the above.

B. Homogeneity

12T. Which of the following is not an assumption or condition that needs to be checked for a paired t-interval? A. Paired Data B. Independent Groups C. Randomization D. 10% Condition E. Nearly Normal Condition

B. Independent Groups

10. Which of the following is not an assumption and/or condition for the paired t-test? A. Nearly Normal Condition B. Independent Groups Assumption C. Paired Data Assumption D. Randomization Condition E. All of the above

B. Independent Groups Assumption

. Insurance companies track life expectancy information to assist in determining the cost of life insurance policies. Last year the average life expectancy of all policyholders was 77 years. ABI Insurance wants to determine if their clients now have a longer life expectancy, on average, so they randomly sample some of their recently paid policies. The insurance company will only change their premium structure if there is evidence that people who buy their policies are living longer than before. Which of the following statement is true about this hypothesis test? A. It is a two tailed test about a proportion. B. It is a one tailed test about a mean. C. It is a one tailed test about a proportion. D. It is a two tailed test about a mean. E. None of the above.

B. It is a one tailed test about a mean.

1. A small business ships specialty homemade candies to anywhere in the world. Past records indicate that the weight of orders is normally distributed. Suppose a random sample of 16 orders is selected and each is weighed. The sample mean was found to be 110 grams with a standard deviation of 14 grams. Which of the following statements is true? A. The sampling distribution for the sample mean follows the t-distribution with 16 degrees of freedom. B. The sampling distribution for the sample mean follows the t-distribution with 15 degrees of freedom. C. The mean of the sampling distribution for the sample mean is 110 grams. D. The sampling distribution for the sample mean is Normal with a mean of 110 grams and standard deviation of 14 grams. E. The standard error is 14 grams.

B. The sampling distribution for the sample mean follows the t-distribution with 15 degrees of freedom.

1. In a metal fabrication process, metal rods are produced to a specified target length of 15 feet. Suppose that the lengths are normally distributed. A quality control specialist collects a random sample of 16 rods and finds the sample mean length to be 14.8 feet and a standard deviation of 0.65 feet. Which of the following statements is true? A. The sampling distribution for the sample mean follows the t-distribution with 16 degrees of freedom. B. The sampling distribution for the sample mean follows the t-distribution with 15 degrees of freedom. C. The mean of the sampling distribution for the sample mean is 14.8 feet. D. The sampling distribution for the sample mean is Normal with a mean of 14.8 feet and standard deviation of .65 feet. E. The standard error is 0.65 feet.

B. The sampling distribution for the sample mean follows the t-distribution with 15 degrees of freedom.

2. Vending machines on a college campus offer a variety of snacks. The purchasing agent believes that each type of snack is equally preferred by students and consequently orders equal quantities. The null hypothesis to test his belief can be worded as A. The types of snacks are not uniformly distributed among the students buying snacks. B. The types of snacks are uniformly distributed among the students buying snacks. C. The types of snacks are independent from each other. D. The distribution of type of snack purchases follows the normal distribution. E. None of the above.

B. The types of snacks are uniformly distributed among the students buying snacks.

11T. A sample of 30 year fixed mortgage rates at 12 randomly chosen credit unions yields a mean rate of 6.65 % and a sample standard deviation of 0.38%. A sample of 30 year fixed mortgage rates at 16 randomly selected banks yields a mean rate of 7.05% and a sample standard deviation of 0.22%. Are the mean rates different between credit unions and banks? Relevant output is shown below. Which of the following is true? <b>DATA</b> A. This is a paired design. B. This is a test of two means from independent samples. C. This is a one tailed test. D. Both A and C. E. Both B and C.

B. This is a test of two means from independent samples.

5. Top management of a large multinational corporation wants to create a culture of innovativeness and change. A consultant hired to assess the company's organizational culture finds that only 15% of employees are open to new ideas and approaches toward their work. Consequently the company conducts a program for employees in order to reinforce the new corporate philosophy. After the program is completed, employees are surveyed to see if a greater percentage is now open to innovativeness and change. The correct alternative hypothesis is A. p = 0.15 B. p > 0.15 C. p < 0.15 D. μ > 0.15 E. μ ≠ 0.15

B. p > 0.15

1. A consumer group was interested in comparing the operating time of cordless toothbrushes manufactured by two different companies. Group members took a random sample of 18 toothbrushes from Company A and 15 from Company B. Each was charged overnight and the number of hours of use before needing to be recharged was recorded. Company A toothbrushes operated for an average of 119.7 hours with a standard deviation of 1.74 hours; Company B toothbrushes operated for an average of 120.6 hours with a standard deviation of 1.72 hours. The t-test for two means is appropriate in this situation because A. the two companies are dependent. B. the two companies are independent. C. the two companies are matched samples. D. the observations are paired. E. None of the above.

B. the two companies are independent.

1*. Data were collected on annual personal time (in hours) taken by a random sample of 16 women and 7 men employed by a medium sized company. The women took an average of 24.75 hours of personal time per year with a standard deviation of 2.84 hours. The men took an average of 21.89 hours of personal time per year with a standard deviation of 3.29 hours. The Human Resources Department believes that women tend to take more personal time than men because they tend to be the primary child care givers in the family. The ttest for two means is appropriate in this situation because A. women and men are dependent samples. B. women and men are independent samples. C. women and men are matched samples. D. the observations are paired. E. None of the above.

B. women and men are independent samples.

8. Suppose that you are conducting a two tailed test about a proportion at the 0.01 level of significance. The correct critical value(s) to be used in drawing a conclusion is (are) A. ± 1.96 B. ±2.575 C. -1.645 D. ±1.645 E. 1.96

B. ±2.575

8. A mid-sized company has decided to implement an enterprise resource planning (ERP) system, and management suspects that many of its employees are concerned about the planned implementation. Managers are considering holding informational workshops to help decrease anxiety levels among employees. They randomly select 16 employees to participate in a pilot workshop. These employees were given a questionnaire to measure anxiety levels about ERP before and after participating in the workshop. If we let d = postworkshop anxiety level - pre-workshop anxiety level, the correct alternative hypothesis to determine if this approach was successful is A. μd = 0 B. μd < 0 C. μd > 0 D. μd ≠ 0 E. μd ≤ 0

B. μd < 0

8. A real estate agency, located in a metropolitan area in the northeastern U.S., kept data on the various types of properties purchased in the area. Historically, 15% of purchases were for condominiums, 30% were for townhouses, 40% for single family homes, 10% for commercial properties and 5% for land. With changing demographics, the agency wondered if the current distribution matches the historical distribution. Recent data showed the following: The value of the Chi-square test statistic is A. χ 2 = 5.993 B. χ 2 = 62.538 C. χ 2 = 101.482 D. χ 2 = 77.431 E. χ 2 = 8.101

B. χ 2 = 62.538

7. An army depot that overhauls ground mobile radar systems is interested in improving its processes. One problem involves troubleshooting a particular component that has a high failure rate after it has been repaired and reinstalled in the system. The shop floor supervisor believes that having standard work procedures in place will reduce the time required for troubleshooting this component. Time (in minutes) required troubleshooting this component without and with the standard work procedure is recorded for a sample of 19 employees. The standard error of the mean difference is <b>CHART<b> A. 25.105 B. 2.307 C. 0.529 D. 4.3589 E. None of the above.

C. 0.529

4. Grandma Gertrude's Chocolates, a family owned business, has an opportunity to supply its product for distribution through a large coffee house chain. However, the coffee house chain has certain specifications regarding cacao content as it wishes to advertise the health benefits (antioxidants) of the chocolate products it sells. In order to determine the mean % cacao in its dark chocolate products, quality inspectors sample 36 pieces. They find a sample mean of 55% with a standard deviation of 4%. The correct value of t* to construct a 90% confidence interval for the true mean % cacao is A. 2.797 B. 1.711 C. 1.690 D. 2.030 E. 1.318

C. 1.690

4. Grandma Gertrude's Chocolates, a family owned business, has an opportunity to supply its product for distribution through a large coffee house chain. However, the coffee house chain has certain specifications regarding cacao content as it wishes to advertise the health benefits (antioxidants) of the chocolate products it sells. In order to determine the mean % cacao in its dark chocolate products, quality inspectors sample 36 pieces. They find a sample mean of 55% with a standard deviation of 4%. The correct value of t* to construct a 90% confidence interval for the true mean % cacao is A. 2.797 B. 1.711 C. 1.690 D. 2.030 E. 1.318

C. 1.690

7. A real estate agency, located in a metropolitan area in the northeastern U.S., kept data on the various types of properties purchased in the area. Historically, 15% of purchases were for condominiums, 30% were for townhouses, 40% for single family homes, 10% for commercial properties and 5% for land. With changing demographics, the agency wondered if the current distribution matches the historical distribution. Recent data showed the following: Based on the historical distribution, we would expect how many homes to be purchased? A. 121 B. 122.54 C. 130 D. 129.95 E. 100

C. 130

5. Data were collected on annual personal time (in hours) taken by a random sample of 16 women and 20 men employed by a medium-sized company. The women took an average of 24.75 hours of personal time per year with a standard deviation of 2.84 hours. The men took an average of 20.5 hours of personal time per year with a standard deviation of 2.75 hours. The pooled estimate of the variance is A. 264.6715 B. 2.790 C. 7.785 D. 12.998 E. None of the above.

C. 7.785

7. A pharmaceutical company wants to answer the question whether it takes longer than 45 seconds for a drug in pill form to dissolve in the gastric juices of the stomach. A sample was taken from patients taken the given drug in pill form and times for the pills to be dissolved were measured. b. State assumptions of the test. A. The subjects must be part of a medical study group investigating the drug. B. The subjects in the sample must be randomly selected from a population. C. B and D are required conditions. D. The sample data must come from a normally distributed population of observations for the variable under study. E. None of the above.

C. B and D are required conditions.

1. Vending machines on a college campus offer a variety of snacks. The purchasing agent believes that each type of snack is equally preferred by students and consequently orders equal quantities. The number of snacks sold from vending machines on this campus for the last six months is shown in the following table. The appropriate test to see if the purchasing agent is correct is the A. Chi-square test of independence. B. Z-test for two proportions. C. Chi-square goodness-of-fit test. D. Chi-square test of homogeneity. E. Normality test.

C. Chi-square goodness-of-fit test.

2. Data were collected on annual personal time (in hours) taken by a random sample of 16 women (group1) and 7 men (group 2) employed by a medium sized company. The women took an average of 24.75 hours of personal time per year with a standard deviation of 2.84 hours. The men took an average of 21.89 hours of personal time per year with a standard deviation of 3.29 hours. The Human Resources Department believes that women tend to take more personal time than men because they tend to be the primary child care givers in the family. The correct null and alternative hypotheses to test this belief are A. H0: μ1 - μ2 = 0 and HA: μ1 - μ2 < 0. B. H0: μ1 - μ2 = 0 and HA: μ1 - μ2 ≠ 0. C. H0: μ1 - μ2 = 0 and HA: μ1 - μ2 > 0. D. H0: μ1 - μ2 > 0 and HA: μ1 - μ2 < 0. E. None of the above.

C. H0: μ1 - μ2 = 0 and HA: μ1 - μ2 > 0.

13T. Chris Columbus is responsible for controlling inventory levels for four types of sailboats sold by his company. Chris takes a sample of 48 boats sold over the past several months to determine if demand is the same for each type. His results are as follows: The correct null hypothesis to be tested is A. Type of boat and demand are related. B. The demand differs for each type of boat. C. The demand is the same for each type of boat. D. Both A and B. E. Both A and C.

C. The demand is the same for each type of boat.

19T. An urban planning group is interested in estimating the difference in mean household income between two neighborhoods. They obtain the following 95% confidence interval: 95% CI for difference: (-5693, -4107). Which of the following is true? A. This is a paired design. B. There is no significant difference in the mean household incomes between the two neighborhoods at α = 0.05. C. There is a significant difference in the mean household incomes between the two neighborhoods at α = 0.05. D. Both A and B. E. Both A and C.

C. There is a significant difference in the mean household incomes between the two neighborhoods at α = 0.05.

2. A report on the U.S. economy indicates that 28% of Americans have experienced difficulty in making mortgage payments. A news organization randomly sampled 400 Americans from 10 cities named the "fastest dying cities in the U.S." (Forbes Magazine, August 2008) and found that 136 reported such difficulty. Does this indicate that the problem is more severe among these cities? The correct value of the test statistic for testing this claim is A. z = -1.28 B. z = -2.67 C. z = 2.67 D. z = 1.96 E. z = -1.28

C. z = 2.67

8*. An army depot that overhauls ground mobile radar systems is interested in improving its processes. One problem involves troubleshooting a particular component that has a high failure rate after it has been repaired and reinstalled in the system. The shop floor supervisor believes that having standard work procedures in place will reduce the time required for troubleshooting this component. Time (in minutes) required troubleshooting this component without and with the standard work procedure is recorded for a sample of 19 employees. Assuming that we define our differences as Time without standard work procedure - Time with standard work procedure, the correct alternative hypothesis is A. μd = 0. B. μd < 0. C. μd > 0. D. μd ≠ 0. E. None of the above.

C. μd > 0.

3. An online department store wants to determine if there is an association between coupon redemption and gender. After a special coupon broadcast to its reward members, the following data on coupon redemption at check out were collected. The P-value associated with the calculated Chi-square statistic is 0.0209. At α = 0.05 the correct conclusion is A. to reject the null hypothesis. B. to accept the null hypothesis. C. to conclude that there is an association between coupon redemption and gender. D. Both A and C. E. Both B and C.

D Both A and C

8. Marcy's Consignment shop is based in Port Angeles, Washington. It offers both male and female never or slightly used clothing and accessories on a consignment basis. Marcy's recently redesigned their website and wants to show that sales have increased. The sales manager selects 30 sales records at random from the store's online client list and she finds a mean increase in spending of $3.50 with a standard deviation of $7.20. The resulting P-value for anαof 0.05 is A. 0.012 B. 0.315 C. 0.630 D. 0.006 E. 0.024

D. 0.006

10. A pharmaceutical company wants to answer the question whether it takes longer than 45 seconds for a drug in pill form to dissolve in the gastric juices of the stomach. A sample was taken from 8 patients taking the given drug in pill form and times for the pills to be dissolved were measured. The mean was 45.212 sec for the sample data with a standard error of 0.580. Determine the P-value for this test. A. 0.181 B. 0.724 C. 0.649 D. 0.362 E. 0.366

D. 0.362

10. A mid-sized company has decided to implement an enterprise resource planning (ERP) system, and management suspects that many of its employees are concerned about the planned implementation. Managers are considering holding informational workshops to help decrease anxiety levels among employees. They randomly select 16 employees to participate in a pilot workshop. These employees were given a questionnaire to measure anxiety levels about ERP before and after participating in the workshop. At the 90% confidence level, what is the margin of error for the mean difference in anxiety levels preand post-workshop? <b>CHART</b> A. 1.753 B. 1.147 C. 0.287 D. 0.503 E. 2.010

D. 0.503

3. Data were collected on annual personal time (in hours) taken by a random sample of 16 women and 7 men employed by a medium sized company. The women took an average of 24.75 hours of personal time per year with a standard deviation of 2.84 hours. The men took an average of 21.89 hours of personal time per year with a standard deviation of 3.29 hours. The standard error of the sampling distribution for the difference between the two means is A. 2.05 B. 5.02 C. 2.24 D. 1.43 E. 0.48

D. 1.43

3. In a metal fabrication process, metal rods are produced to a specified target length of 15 feet. Suppose that the lengths are normally distributed. A quality control specialist collects a random sample of 16 rods and finds the sample mean length to be 14.8 feet and a standard deviation of 0.65 feet. The 95% confidence interval for the true mean length of rods produced by this process is A. 14.544 to 15.056 ft. B. 14.345 to 15.255 ft. C. 13.912 to 15.688 ft. D. 14.454 to 15.146 ft. E. 13.834 to 15.766 ft.

D. 14.454 to 15.146 ft.

9. A real estate agency, located in a metropolitan area in the northeastern U.S., kept data on the various types of properties purchased in the area. Historically, 15% of purchases were for condominiums, 30% were for townhouses, 40% for single family homes, 10% for commercial properties and 5% for land. With changing demographics, the agency wondered if the current distribution matches the historical distribution. Recent data showed the following: What is the standardized residual associated with Townhouses? A. 23.5 B. 4.85 C. 10.86 D. 2.38 E. Not enough information given to calculate.

D. 2.38

2. A small business ships specialty homemade candies to anywhere in the world. Past records indicate that the weight of orders is normally distributed. Suppose a random sample of 16 orders is selected and each is weighed. The sample mean was found to be 110 grams with a standard deviation of 14 grams. The standard error of the mean is A. 14 grams B. 0.875 grams C. .35 grams D. 3.5 grams E. 27.5 grams

D. 3.5 grams

1. A company that sells eco-friendly cleaning products is concerned that only 19.5% of people who use such products select their brand. A marketing director suggests that the company invest in new advertising and labeling to strengthen its green image. The company decides to do so in a test market so that the effectiveness of the marketing campaign may be evaluated. In this context, committing a Type I error A. Occurs when they conclude that the percentage of customers purchasing the company's brand has increased when in fact it has not. B. Occurs then they conclude that the percentage of customers purchasing the company's brand has not increased when in fact it has. C. Would result in the company wasting money on a new marketing campaign that does not increase the percentage of customers buying their brand. D. Both A and C. E. Both B and C.

D. Both A and C.

10. A large software development firm recently relocated its facilities. Top management is interested in fostering good relations with their new local community and has encouraged their professional employees to engage in local service activities. They believe that the firm's professionals volunteer an average of more than 15 hours per month. If this is not the case, they will institute an incentive program to increase community involvement. A random sample of 24 professionals yields a mean of 16.6 hours and a standard deviation of 2.22 hours. The P-value associated with the resulting test statistic is 0.0009. At α = 0.05, which of the following is the correct conclusion? A. We reject the null hypothesis. B. We fail to reject the null hypothesis. C. The firm shouldn't need to institute an incentive program because the evidence indicates that professional employees volunteer an average of more than 15 hours per month in their local community. D. Both A and C. E. Both B and C.

D. Both A and C.

4. Data were collected on annual personal time (in hours) taken by a random sample of 16 women (group1) and 7 men (group 2) employed by a medium sized company. The women took an average of 24.75 hours of personal time per year with a standard deviation of 2.84 hours. The men took an average of 21.89 hours of personal time per year with a standard deviation of 3.29 hours. The Human Resources Department believes that women tend to take more personal time than men because they tend to be the primary child care givers in the family. The results of the test are t = 2.02 with an associated P-value of 0.0352. The correct conclusion at α = 0.05 is to A. reject the null hypothesis. B. fail to reject the null hypothesis. C. conclude that women take a higher average number of hours of personal time per year compared to men. D. Both A and C. E. Both B and C.

D. Both A and C.

4T. A sample of 30 year fixed mortgage rates at 12 randomly chosen credit unions yields a mean rate of 6.65 % and a sample standard deviation of 0.38%. A sample of 30 year fixed mortgage rates at 16 randomly selected banks yields a mean rate of 7.05% and a sample standard deviation of 0.22%. Are the mean rates different between credit unions and banks? Relevant output is shown below. At the 0.05 level of significance, the correct conclusion is <b>DATA</b> A. Reject the null hypothesis. B. Do not reject the null hypothesis. C. Evidence suggests that there is a significant difference in mean mortgage rates between credit unions and banks. D. Both A and C. E. Both B and C.

D. Both A and C.

5. Vending machines on a college campus offer a variety of drinks. The purchasing agent believes that each type of snack is equally preferred by students and consequently orders equal quantities. The number of snacks sold from vending machines on this campus for the last six months is shown in the following table. The P-value of the calculated Chisquare statistic is 0.0458. At α = 0.05, we should A. reject the null hypothesis. B. not reject the null hypothesis. C. conclude that the purchasing agent was not correct. D. Both A and C. E. Both B and C.

D. Both A and C.

6. Insurance companies track life expectancy information to assist in determining the cost of life insurance policies. Last year the average life expectancy of all policyholders was 77 years. ABI Insurance wants to determine if their clients now have a longer life expectancy, on average, so they randomly sample 20 of their recently paid policies. The sample has a mean of 78.6 years and a standard deviation of 4.48 years. The P-value associated with the resulting test statistic is 0.063. At α = 0.05, which of the following is the correct conclusion? A. We fail to reject the null hypothesis. B. We reject the null hypothesis. C. There is not significant evidence to indicate an increase in average life expectancy. D. Both A and C. E. Both B and C.

D. Both A and C.

9*. An army depot that overhauls ground mobile radar systems is interested in improving its processes. One problem involves troubleshooting a particular component that has a high failure rate after it has been repaired and reinstalled in the system. The shop floor supervisor believes that having standard work procedures in place will reduce the time required for troubleshooting this component. Time (in minutes) required troubleshooting this component without and with the standard work procedure is recorded for a sample of 19 employees. The P-value associated with the calculated test statistic is < 0.001. At α = 0.05, the correct conclusion is to A. reject the null hypothesis. B. fail to reject the null hypothesis. C. conclude that having standard work procedures in place reduces troubleshooting time for this component. D. Both A and C. E. Both B and C.

D. Both A and C.

10. Top management of a large multinational corporation wants to create a culture of innovativeness and change. A consultant hired to assess the company's organizational culture finds that only 15% of employees are open to new ideas and approaches toward their work. Consequently the company conducts a program for employees in order to reinforce the new corporate philosophy. After the program is completed, employees are surveyed to see if a greater percentage is now open to innovativeness and change. Suppose that based on the sample results the company rejects the null hypothesis when in fact it is true. Which of the following statements is correct? A. This is known as a Type II error. B. This is known as a fatal error. C. This led to the conclusion that the percentage of employees open to new ideas did not increase when in fact it did. D. This led to the conclusion that the percentage of employees open to new ideas did increase when in fact it did not. E. This led to a P-value that was greater than the level of significance.

D. This led to the conclusion that the percentage of employees open to new ideas did increase when in fact it did not.

9. A manufacturing plant for recreational vehicles receives shipments from three different parts vendors. There has been a defect issue with some of the electrical wiring in the recreational vehicles manufactured at the plant. The plant manager believes that the defect issue is dependent on the parts vendor. The plant manager reviews a sample of quality assurance inspections from the last six months. The correct value of the test statistic for determining if the plant manager's belief is supported is A. χ 2 = 8.10 B. χ 2 = 6.52 C. χ 2 = 5.03 D. χ 2 = 7.40 E. χ 2 = 9.89

D. χ 2 = 7.40

9. A manufacturer of cream filled donuts wants to make sure that its automatic filling process is on target. Based on a sample of 25 donuts the mean weight of cream filling is estimated to be 15 grams with a standard deviation of 1.5 grams. However, the quality control inspectors wish to estimate the mean weight of cream filling more accurately so that they can be 99% confident that it is within 0.25 grams of the true mean. How many donuts should they sample? A. 150 B. 543 C. 212 D. 410 E. 239

E. 239

9. Top management at a large software company wishes to estimate the average number of hours its firm's professional employees volunteer in the local community. Based on past similar studies, the standard deviation was found to be 2.22 hours. If top management wants to estimate the average number of hours volunteered per month by their professional staff to within one hour with 99% confidence, how many randomly selected professional employees would they need to sample? A. 19 B. 25 C. 54 D. 44 E. 33

E. 33

20T. The residual, or the difference, between the observed frequency and the expected frequency is a reliable indicator. A standardized residual can also be computed for each cell. Which statements are true about standardized residuals? A. Standardized residuals that have a positive value mean that the cell was overrepresented in the actual sample, compared to the expected frequency. B. The standardized residual can be compared against the critical z-value for your α level to determine significance. C. Standardized residuals can be used to test the null hypothesis that the actual frequency equals the expected frequency for a specific cell versus the research hypothesis of a difference greater than zero. D. Standardized residuals that have a negative value mean that the cell was underrepresented in the actual sample, compared to the expected frequency. E. All of the above.

E. All of the above.

2. A large software development firm recently relocated its facilities. Top management is interested in fostering good relations with their new local community and has encouraged their professional employees to engage in local service activities. They believe that the firm's professionals volunteer an average of more than 15 hours per month. If this is not the case, they will institute an incentive program to increase community involvement. Based on data collected they perform the appropriate hypothesis test. A Type II error in this context means A. They failed to detect that the average number of hours volunteered by the firm's professional employees is more than 15 hours when in fact it is. B. They would decide not to institute an incentive program to increase community involvement when they should have. C. They would waste money instituting an incentive program to increase community involvement among its professional employees that was not needed. D. Both A and B. E. Both A and C.

E. Both A and C.

10. A manufacturing plant for recreational vehicles receives shipments from three different parts vendors. There has been a defect issue with some of the electrical wiring in the recreational vehicles manufactured at the plant. The plant manager believes that the defect issue is dependent on the parts vendor. The plant manager reviews a sample of quality assurance inspections from the last six months. The P-value of the calculated Chisquare statistic is 0.1161. At α = 0.05, we should A. reject the null hypothesis. B. not reject the null hypothesis. C. conclude that the defects do not vary by vendor. D. both A and C. E. both B and C.

E. both B and C.

9. Managers are considering holding informational workshops to help decrease anxiety levels among employees. They randomly select 20 employees to participate in a pilot workshop. These employees were given a questionnaire to measure anxiety levels before and after participating in the workshop. A test was performed to determine if the workshop was successful in decreasing anxiety levels. The test results yielded a P-value of 0.008. The correct conclusion at α = .05 is A. to accept the null hypothesis. B. to reject the null hypothesis. C. to conclude that participating in the workshop decreases employee anxiety about ERP. D. both A and C. E. both B and C.

E. both B and C.

. A manufacturing plant for recreational vehicles receives shipments from three different parts vendors. There has been a defect issue with some of the electrical wiring in the recreational vehicles manufactured at the plant. The plant manager believes that the defect issue is dependent on the parts vendor. The plant manager reviews a sample of quality assurance inspections from the last six months. The expected number of rejected parts from Perfect Parts Co. is A. 53 B. 51.51 C. 57.68 D. 61.81 E. 171

c 57.68

1. An online department store wants to determine if there is an association between coupon redemption and gender. After a special coupon broadcast to its reward members, the following data on coupon redemption at check out were collected. Which Chi-square test is most appropriate for this situation? A. Goodness of Fit B. Homogeneity C. Independence D. Proportional E. None of the above.

c. Independence

3. In a metal fabrication process, metal rods are produced to a specified target length of 15 feet. Suppose that the lengths are normally distributed. A quality control specialist collects a random sample of 16 rods and finds the sample mean length to be 14.8 feet and a standard deviation of 0.65 feet. The 95% confidence interval for the true mean length of rods produced by this process is A. 14.544 to 15.056 ft. B. 14.345 to 15.255 ft. C. 13.912 to 15.688 ft. D. 14.454 to 15.146 ft. E. 13.834 to 15.766 ft.

d. 14.454 to 15.146 ft