Question: Suppose we wished to know if model A or B was safer based on the results of the safety tests described in problem two. To make a decision we randomly selected a sample of 25 model A seats and subjected them to the safety test. The mean score was 6.7 with a standard deviation of .28. A sample of 20 model B seats were selected at random and subject to the same test. The mean score was 6.9 with a standard deviation of .36.
A. Write appropriate non-directional null and alternative hypotheses in words and symbols.
B. Test the null at the 0.01 level of significance. What is the p-value? Make a decision about rejecting or failing to reject the null based on the p-value?
C. Draw a conclusion. ( The seats do or do not have differences in safety as measured by this test).
D. If you had conducted the test at the .05 level, would the decision have changed? Show work, justify answer.