Answer: Large Data Sets from Appendix B. In Exercises 17 and 18, use the data set from

Waiting in Line The Jefferson Valley Bank once had a separate customer waiting line at each teller window, but it now has a single waiting line that feeds the teller windows as vacancies occur. The standard deviation of customer waiting times with the old multipleline configuration was 1.8 min. Listed below is a simple random sample of waiting times (minutes) with the single waiting line. The 10 sample values have a standard deviation of 0.5 min. a. When the bank changed from multiple waiting lines to a single line, how was the mean waiting time affected? 6.5 6.6 6.7 6.8 7.1 7.3 7.4 7.7 7.7 7.7 b. When the bank changed from multiple waiting lines to a single line, how was the variation among waiting times affected? c. What improvement occurred with the change from multiple waiting lines to a single line? d. What procedure can be used to determine that the single waiting line is better?

Requirements If we want to use the sample data from Exercise 1 to test the claim that the sample is from a population with a standard deviation less than 1.8 min, we must satisfy the requirements of having a simple random sample and a normally distributed population. In Exercise 1 it was stated that the sample is a simple random sample. a. In general, how does the normality requirement for a hypothesis test of a claim about a standard deviation differ from the normality requirement for a hypothesis test of a claim about a mean? b. What methods can be used to determine whether the normality requirement is satisfied?

Confidence Interval Method of Hypothesis Testing Assume that we want to use the sample data from Exercise 1 to test the claim that the sample is from a population with a standard deviation less than 1.8 min we will use a 0.05 significance level to test that claim. If we want to use the confidence interval method of testing hypotheses, what level of confidence should be used for the confidence interval? Will the conclusion based on the confidence interval be the same as the conclusion based on a hypothesis test that uses the Pvalue method or the critical value method?

Hypothesis Test For the sample data from Exercise 1, we have s = 0.5 and we want to use that sample to test the claim that the sample is from a population with a standard deviation less than 1.8 min (as it was in the past with multiple waiting lines). a. Identify the null and alternative hypotheses. b. Find the value of the test statistic. c. Using technology, the Pvalue is found to be 0.0001. What should we conclude about the null hypothesis? d. Given that the Pvalue is 0.0001, what should we conclude about the original claim? e. What does the conclusion suggest about the effectiveness of the change from multiple waiting lines to a single line?

Testing Claims About Variation. In Exercises 516, test the given claim. Identify the null hypothesis, alternative hypothesis, test statistic, Pvalue or critical value(s), conclusion about the null hypothesis, and final conclusion that addresses the original claim. Assume that a simple random sample is selected from a normally distributed population.Cans of Coke Data Set 19 in Appendix B includes volumes (oz) of a simple random sample of 36 cans of regular Coke. Those volumes have a mean of 12.19 oz and a standard deviation of 0.11 oz, and they appear to be from a normally distributed population. If we want the filling process to work so that almost all cans have volumes between 11.8 oz and 12.4 oz, the range rule of thumb can be used to estimate that the standard deviation should be less than 0.15 oz. Use the sample data to test the claim that the population of volumes has a standard deviation less than 0.15 oz. Use a 0.05 significance level.

Testing Claims About Variation. In Exercises 516, test the given claim. Identify the null hypothesis, alternative hypothesis, test statistic, Pvalue or critical value(s), conclusion about the null hypothesis, and final conclusion that addresses the original claim. Assume that a simple random sample is selected from a normally distributed population.Cans of Pepsi Repeat the preceding exercise using these statistics from a simple random sample of cans of regular Pepsi: n = 36 , x = 12.29 oz , s = 0.09 oz.

Testing Claims About Variation. In Exercises 516, test the given claim. Identify the null hypothesis, alternative hypothesis, test statistic, Pvalue or critical value(s), conclusion about the null hypothesis, and final conclusion that addresses the original claim. Assume that a simple random sample is selected from a normally distributed population.Weights of Pennies Data Set 21 in Appendix B includes a simple random sample of 37 weights of post1983 pennies. Those 37 weights have a mean of 2.49910 g and a standard deviation of 0.01648 g. U.S. Mint specifications require that pennies be manufactured so that the mean weight is 2.500 g. A hypothesis test will verify that the sample appears to come from a population with a mean of 2.500 g as required, but use a 0.05 significance level to test the claim that the population of weights has a standard deviation less than the specification of 0.0230 g

Testing Claims About Variation. In Exercises 516, test the given claim. Identify the null hypothesis, alternative hypothesis, test statistic, Pvalue or critical value(s), conclusion about the null hypothesis, and final conclusion that addresses the original claim. Assume that a simple random sample is selected from a normally distributed population.Weights of Pennies The preceding exercise involved the claim that post1983 pennies have weights with a standard deviation less than 0.0230 g. Data Set 21 in Appendix B includes the weights of a simple random sample of 35 pre1983 pennies, and that sample has a standard deviation of 0.03910 g. Use a 0.05 significance level to test the claim that pre1983 pennies have weights with a standard deviation greater than 0.0230 g. Does it appear that weights of pre1983 pennies vary more than those of post1983 pennies?

Testing Claims About Variation. In Exercises 516, test the given claim. Identify the null hypothesis, alternative hypothesis, test statistic, Pvalue or critical value(s), conclusion about the null hypothesis, and final conclusion that addresses the original claim. Assume that a simple random sample is selected from a normally distributed population.. Pulse Rates of Men A simple random sample of 40 men results in a standard deviation of 10.3 beats per minute (based on Data Set 1 in Appendix B). The normal range of pulse rates of adults is typically given as 60 to 100 beats per minute. If the range rule of thumb is applied to that normal range, the result is a standard deviation of 10 beats per minute. Use the sample results with a 0.05 significance level to test the claim that pulse rates of men have a standard deviation equal to 10 beats per minute.

Testing Claims About Variation. In Exercises 516, test the given claim. Identify the null hypothesis, alternative hypothesis, test statistic, Pvalue or critical value(s), conclusion about the null hypothesis, and final conclusion that addresses the original claim. Assume that a simple random sample is selected from a normally distributed population.Pulse Rates of Women Repeat the preceding exercise using the pulse rates of women listed in Data Set 1 of Appendix B. For this sample, n = 40 and s = 11.6 beats per minute.

Testing Claims About Variation. In Exercises 516, test the given claim. Identify the null hypothesis, alternative hypothesis, test statistic, Pvalue or critical value(s), conclusion about the null hypothesis, and final conclusion that addresses the original claim. Assume that a simple random sample is selected from a normally distributed population.Cigarette Tar A simple random sample of 25 filtered 100mm cigarettes is obtained, and the tar content of each cigarette is measured. The sample has a standard deviation of 3.7 mg (based on Data Set 10 in Appendix B). Use a 0.05 significance level to test the claim that the tar content of filtered 100mm cigarettes has a standard deviation different from 3.2 mg, which is the standard deviation for unfiltered kingsize cigarettes.

Testing Claims About Variation. In Exercises 516, test the given claim. Identify the null hypothesis, alternative hypothesis, test statistic, Pvalue or critical value(s), conclusion about the null hypothesis, and final conclusion that addresses the original claim. Assume that a simple random sample is selected from a normally distributed population.Analysis of Pennies In an analysis investigating the usefulness of pennies, the cents portions of 100 randomly selected credit card charges from the author are recorded, and they have a mean of 47.6 cents and a standard deviation of 33.5 cents. If the amounts from 0 cents to 99 cents are all equally likely, the mean is expected to be 49.5 cents and the population standard deviation is expected to be 28.866 cents. Use a 0.01 significance level to test the claim that the sample is from a population with a standard deviation equal to 28.866 cents. If the amounts from 0 cents to 99 cents are all equally likely, is the requirement of a normal distribution satisfied? If not, how does that affect the conclusion?

Testing Claims About Variation. In Exercises 516, test the given claim. Identify the null hypothesis, alternative hypothesis, test statistic, Pvalue or critical value(s), conclusion about the null hypothesis, and final conclusion that addresses the original claim. Assume that a simple random sample is selected from a normally distributed population.Ages of Race Car Drivers Listed below are the ages (years) of randomly selected race car drivers (based on data reported in USA Today). Most people in the general population have ages that vary between 0 and 90 years, so use of the range rule of thumb suggests that ages in the general population have a standard deviation of 22.5 years. Use a 0.01 significance level to test the claim that the standard deviation of ages of all race car drivers is less than 22.5 years. 32 32 33 33 41 29 38 32 33 23 27 45 52 29 25

Testing Claims About Variation. In Exercises 516, test the given claim. Identify the null hypothesis, alternative hypothesis, test statistic, Pvalue or critical value(s), conclusion about the null hypothesis, and final conclusion that addresses the original claim. Assume that a simple random sample is selected from a normally distributed population.Highway Speeds Listed below are speeds (mi/h) measured from southbound traffic on I280 near Cupertino, California (based on data from SigAlert). This simple random sample was obtained at 3:30 p.m. on a weekday. Use a 0.05 significance level to test the claim of the highway engineer that the standard deviation of speeds is equal to 5.0 mi/h. 62 61 61 57 61 54 59 58 59 69 60 67

Testing Claims About Variation. In Exercises 516, test the given claim. Identify the null hypothesis, alternative hypothesis, test statistic, Pvalue or critical value(s), conclusion about the null hypothesis, and final conclusion that addresses the original claim. Assume that a simple random sample is selected from a normally distributed population.Aircraft Altimeters The Skytek Avionics company uses a new production method to manufacture aircraft altimeters. A simple random sample of new altimeters resulted in the errors listed below. Use a 0.05 level of significance to test the claim that the new production method has errors with a standard deviation greater than 32.2 ft, which was the standarddeviation for the old production method. If it appears that the standard deviation is greater, does the new production method appear to be better or worse than the old method? Should the company take any action? 42 78 22 72 45 15 17 51 5 53 9 109

Testing Claims About Variation. In Exercises 516, test the given claim. Identify the null hypothesis, alternative hypothesis, test statistic, Pvalue or critical value(s), conclusion about the null hypothesis, and final conclusion that addresses the original claim. Assume that a simple random sample is selected from a normally distributed population.IQ of Professional Pilots The Wechsler IQ test is designed so that the mean is 100 and the standard deviation is 15 for the population of normal adults. Listed below are IQ scores of randomly selected professional pilots. It is claimed that because professional pilots are a more homogeneous group than the general population, they have IQ scores with a standard deviation less than 15. Test that claim using a 0.05 significance level. 121 116 115 121 116 107 127 98 116 101 130 114

Large Data Sets from Appendix B. In Exercises 17 and 18, use the data set from Appendix B to test the given claim. Identify the null hypothesis, alternative hypothesis, test statistic, Pvalue or critical value(s), conclusion about the null hypothesis, and final conclusion that addresses the original claimCans of Diet Coke Repeat Exercise 5 using the volumes (oz) of cans of diet Coke

Large Data Sets from Appendix B. In Exercises 17 and 18, use the data set from Appendix B to test the given claim. Identify the null hypothesis, alternative hypothesis, test statistic, Pvalue or critical value(s), conclusion about the null hypothesis, and final conclusion that addresses the original claimWeights of Pennies Data Set 21 in Appendix B includes a simple random sample of wheat pennies. U.S. Mint specifications now use a standard deviation of 0.0230 g for weights of pennies. Use a 0.01 significance level to test the claim that wheat pennies were manufactured so that their weights have a standard deviation equal to 0.0230 g.