9. Alex wants to know whether college major affects happiness ratings. To that end, she recruits 15 people to be in her study-5 psychology majors, 5 biology majors and 5 math majors. She asks each of them to rate their happiness on a scale from 1-10. The data follows. Is there a significant difference among college majors in their happiness ratings? (22 points) Psychology 7 8 6 9 8 Biology 5 7 4 5 3 Math 4 3 6 S 10. In question 9, if you had conducted a t-test on happiness ratings between biology majors and math majors, what would your decision have been? (1 point) 11. If the distribution of happiness ratings is approximately normal in the general student population, what proportion of samples of size n = 64 would have a mean score between 5 and 7, if u = 6.2 and a = 4? (5 points)