A researcher is interested in comparing the response times of two different cab companies. Companies A and B were each called at 50 randomly selected times. The calls to company A were independently made from the calls to company B. Company A had a mean response time of 8.5 minutes with a standard deviation of 1.8 minutes. Company B had a mean response time of 5.5 minutes with a standard deviation of 1.6 minutes. Use .05 significance level to test the claim that the mean response time for company A differs from the mean response time for company B.
1. State the null and alternative hypotheses symbolically and identify which represents the claim.
2. Determine whether the hypothesis test is a one-tailed test or a two-tailed test and whether or not to use a z-test or a t-test. Explain reasoning.
3. Identify the critical value(s) and identify the rejection region(s).
4. Use the appropriate test to find the appropriate test statistic. You can use technology for this question but please attach your results which must show your work.
5. Based on your test statistic and your rejection region, what is your decision.
6. Interpret your decision in context of the original claim.
7. Construct a 95% confidence interval estimate of the difference between the mean response times for Company A and Company B. Interpret your interval in context of the original claim.