4 (Chapter 13) Cash Offer for a Used Car A consumer organization decided to assess if the age of a used car owner has any effect on the size of a cash offer for a used car. In particular, they hypothesize that dealerships offer more to middle-aged car owners as compared to young car owners, on average. A 5% significance level was selected. The study involved 12 young people (6 men and 6 women all between 18 and 24 years old, referred to as group 1) and 12 middle-aged people (6 men and 6 women all between 36 and 45 years old, referred to as group 2). These 24 people acted as the owner of a specific 6-year-old used car. A total of 24 different car dealerships were selected at random from those in the Detroit area. Each subject in the study went to one car dealership to obtain a cash offer for the same used car. The resulting cash offers in hundreds of dollars are available in the data set called cashoffer.sav. a. The null hypothesis can be stated as H0: 1 - 2 = 0. Which of the following is the appropriate direction for the alternative hypothesis Ha: 1 - 2 _____ 0? i. greater than (>) ii. less than (<) iii. not equal to (1 pts) b. Consider the following incorrect definition for the first population mean: 1 = the sample mean cash offer for the young used car owners How should you complete this statement to improve this definition? Change the word _______________ to _______________. (1 pts) (CLICK TO ENTER ANSWER) c. Use SPSS to perform the two-sample t-test. You can copy and paste just the table with the Independent Samples Test results below OR save that test output table as a jpg and upload it. (1.5 pts) UPLOAD (You need FLASH to upload files. Only JPEG, GIF, PNG files accepted.) (CLICK TO ENTER ANSWER) d. What is the appropriate null hypothesis for Levenes test? i. The two sample variances are equal. ii. The two sample variances are similar. iii. The two population variances are equal. iv. The two population variances are similar. (1 pts) e. Based on Levenes test, which t-test results will you report? i. Two independent samples general (unpooled) t-test ii. Two independent samples pooled t-test (1 pts) f. Report the t-test statistic value, and the p-value for the hypothesis in part (a). (2 pts) (CLICK TO ENTER ANSWER) g. What is the distribution that would be used to find the p-value for the t-test? (1 pts) (CLICK TO ENTER ANSWER) h. Clearly state the appropriate conclusion to this investigation in context. (2 pts) (CLICK TO ENTER ANSWER) i. If there really was no effect of the age of the used car owner on the mean cash offer (for the two populations), what would be the expected value of the t-test statistic? i. 0 ii. 0.05 iii. 1.96 iv. -3.20 v. cannot tell as we do not know the values of the two population means (0.5 pts) j. A summer intern who was helping on this project for the consumer organization remembered that there was a normal model condition required for conducting this test. He created the following graph for assessing that normality condition. Clearly explain in one sentence why this is not the appropriate graph to examine and suggest what should be examined instead. (1 pts) (CLICK TO ENTER ANSWER)