#10 & 16 all work shown

E Hou = 10 Hi le > 10 A random sample of 10 observations is selected from a normal population. The sample mean was 12 and the sample standard deviation 3. Using the .05 significance level: a. State the decision rule. b. Compute the value of the test statistic, c. What is your decision regarding the null hypothesis? 10. Given the following hypotheses: Hou = 400 Hip. + 400 A random sample of 12 observations is selected from a normal population. The sample mean was 407 and the sample standard deviation 6. Using the .01 significance level: a. State the decision rule. b. Compute the value of the test statistic. c. What is your decision regarding the null hypothesis? 11. The Rocky Mountain district sales manager of Rath Publishing Inc., a college textbook pub lishing company, claims that the sales representatives make an average of 40 sales calls per week on professors. Several reps say that this estimate is too low, To investigate, a random sample of 28 sales representatives reveals that the mean number of calls made last week was 42. The standard deviation of the sample is 2.1 calls. Using the .05 significance level, can we conclude that the mean number of calls per salesperson per week is more than 40? 12. The management of White Industries is considering a new method of assembling its golf cart. The present method requires 42.3 minutes, on the average, to assemble a cart. The mean assembly time for a random sample of 24 carts, using the new method, was 40.6 minutes, and the standard deviation of the sample was 2.7 minutes, Using the . 10 level of significance, can we conclude that the assembly time using the new method is faster? 13. The mean income per person in the United States is $40,000, and the distribution of in comes followONE-SAMPLE TESTS OF HYPOTHESIS 339 16. Given the following hypotheses: Hop = 100 Hi: w / 100 A random sample of six resulted in the following values: 118, 105, 112, 119, 105, and 111. Assume a normal population. Using the .05 significance level, can we conclude the mean is different from 100? a. State the decision rule. b. Compute the value of the test statistic. c. What is your decision regarding the null hypothesis? d. Estimate the p-value. 17. The amount of water consumed each day by a healthy adult follows a normal distribution with a mean of 1.4 liters. A health campaign promotes the consumption of at least 2.0 liters per RY DATA FILE, please visit day. A sample of 10 adults after the campaign shows the following consumption in liters: www.mhhe.com/lind16e 1.5 1.6 1.5 1.4 1.9 1.4 1.3 1.9 1.8 1.7 At the .01 significance level, can we conclude that water consumption has increased? Cal- culate and interpret the p-value. 18. The liquid chlorine added to swimming pools to combat algae has a relatively short shelf life before it loses its effectiveness. Records indicate that the mean shelf life of a 5-gallon jug of chlorine is 2,160 hours (90 days). As an experiment, Holdlonger was added to the For DATA FILE, please visit chlorine to find whether it would increase the shelf life. A sample of nine jugs of chlorine www.mhhe.com/lind16e had these shelf lives (in hours): 2,159 2,170 2,180 2,179 2,160 2,167 2,171 2,181 2,185 At the .025 level, has Holdlonger increased the shelf life of the chlorine? Estimate the p-value. 19. A Washington, D.C., "think tank" announces the typical teenager sent 50 text messages in 2013. To update that estimate, you phone a sample of 12 teenagers and ask were