Chapter 11, Problem 20P

A researcher uses a matched-subjects design to investigate whether single people with pets are happier than singles without pets. A mood inventory survey is given to a group of 20- to 29-year-old non-pet owners and a similar age group of pet owners. The pet owners are matched one to one with the non-pet owners for income, number of close friendships, and general health. The data follow:

  

a. Is there a significant difference in the mood scores for non-pet owners versus pet owners? Test with $\alpha$ = .05 for two tails.

  b Construct the 95% confidence interval to estimate the size of the mean difference in mood between the population of pet owners and the population of non-per owners, (You should find that a mean difference of $\mu$_D = 0 is an acceptable value, which is consistent with the conclusion from the hypothesis test.)