A group of researchers quantified the absorption of electromagnetic energy and the thermal effects from microwaves. The results were obtained from experiments conducted on chimpanzees. The blood pressure values (mmHg) for the control group (9 chimpanzees) and the test group (13 chimpanzees) are as follows:

Group 1 (control group): sample mean = 104 mmHg, sample standard deviation = 7 mmHg

Group 2 (test group): sample mean = 125 mmHg, sample standard deviation = 13 mmHg

a. Is there evidence to support the claim that the test group has lower mean blood pressure than the control group? State the appropriate hypotheses and use=0.04. Assume that the samples are independent, both populations are normally distributed, but the variances are not equal. What is the P-value for this test?

b. Calculate a confidence interval to answer the question in part (a).

c. How could we use the confidence interval in part (b) to check the claim that the mean blood pressure from the test group is at least 13 mmHg higher than the control group? State the appropriate hypothesis and use the same assumptions from part (a).