(This problem is similar to the Chapter 9,
Problem 33. However, different data will be used.) We observe that people seem
to be happier when they are wearing a new article of clothing. To test this, we
provide a small random sample of our students with a new T-shirt and instruct
them to wear the shirts all day. At the end of the day, independent judges
ranked the happiness (or what social psychologists call “subjective
well-being”) of each participant. A control group of students is also judged in
terms of happiness, but without the experimental manipulation. The ratings are
below. Lower scores indicate greater happiness. Conduct a Mann–Whitney U test.
Use a two-tailed test and set α=.05.