The Survey of Study Habits and Attitudes (SSHA) is a psychological test that measures the motivation, attitude toward school, and study habits of students. Scores range from 0 to 200. The mean score for students who live on the west coast is about 115.
a) A teacher who suspects that students on the east coast have better attitudes toward school gives the SSHA to 25 students from that part of the country. Their mean score is 132.2, and the standard deviation is 30. Is his hypothesis correct? Use 10% significance level for your test.
b) Construct a 90% confidence interval for the unknown mean of the students on the east coast.