Question: A researcher uses a matched-sample design to investigate whether single people who own pets are generally happier than single without pets. A mood inventory questionnaire is administered 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 are as follows:

Matched Pair Non-Pet Owner Pet Owner

A 10 15

B 9 9

C 11 10

D 11 19

E 5 17

F 9 15

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