Listed below are body temperatures from seven different subjects measured at two different times in a day (from Data Set 3 “Body Temperatures” in Appendix B).

a. Use a 0.05 significance level to test the claim that there is no difference between body temperatures measured at 8 AM and at 12 AM.
b. Construct the confidence interval that could be used for the hypothesis test described in part (a). What feature of the confidence interval leads to the same conclusion reached in part (a)?

Use the listed paired sample data, and assume that the samples are simple random samples and that the differences have a distribution that is approximately normal.

Data Set 3: Body Temperatures 

Body temperatures (ºF) are from 107 subjects taken on two consecutive days at 8 AM and 12 AM (first five rows shown here). SEX is gender of subject, and SMOKE indicates if subject smokes (Y) or does not smoke (N). Data provided by Dr. Steven Wasserman, Dr. Philip Mackowiak, and Dr. Myron Levine of the University of Maryland.