Question

19) -In a crash test at five miles per hour, the mean bumper repair cost for 14  midsize cars was $547 with a standard deviation of $85. In a similar test  of 23 small cars, the mean bumper repair cost was $347 with a standard   deviation of $185. At a = 0.05, can you conclude that the mean bumper repair cost is the same for midsize cars and small cars? a) List the p-value b) accept or reject.

- Last year the average daily change in the Dow Jones Industrial Index was 7.3 points. A random sample of 15 trading days this year showed the average change to be 5.6 points with standard deviation 10.2. Test the claim that the average change in the index is less this year than it was last year. a) List the p-value b) Have we proven that the change is significant? (yes or no) c) what type of error could be made with the type of conclusion drawn from the results of this study?

Answer 1

There is no sufficient evidence to conclude that the mean bumper repair cost is same for midsize cars and small cars.

(b)The change is not significant. There is no sufficient evidence to tell that the change is significant.

(c) We might be making type 2 error because type 2 error is accepting Ho when H1 is true and we are accepting Ho.