MATH 1342 Name Elementary Statistical Methods Lab Ch.10 - Hypothesis Testing One Sample Critical Thinking: Communication Skills; Empirical Quantitative Skills Suppose you are the manager of Speedy Oil Change which claims that it will change the oil in customers' cars in less than 30 minutes on average. Further suppose that several complaints have been filed from customers stating that their oil change took longer than 30 minutes. Upper-level management at Speedy Oil Change headquarters has requested that you investigate the complaints. To begin your investigation, you randomly audit 38 oil changes performed by Speedy Oil Change and record the time each customer waited for the oil change. The number of minutes to complete each of the 38 oil changes is reported below. 42 25 19 11 10 27 41 27 22 26 28 32 17 15 25 35 32 22 13 31 17 30 33 25 18 24 28 21 40 19 34 14 23 22 (data similar to http://org_elon.edw/econ/sac/Descriptive.htm) In the questions below, you will test if the mean is significantly less than 30 minutes at a significance level of 0.01. 1. List the requirements that should be met for this hypothesis test. 2. Write the null and alternative hypothesis. 3. Calculate the test statistic and the P-value. Label each accordingly. 4. Would you reject the null hypothesis? Justify your answer using a complete sentence and proper grammar. 5. Is the company fulfilling its promise to "change the oil in customers' cars in less than 30 minutes on average?'