Examples:

1. The Survey of Study Habits and Attitudes (SSHA) is a psychological test that measures the motivation, attitude towards school, and study habits of students. Scores range from 0 to 200 with higher scores indicating a better attitude. The mean score for US college students is about 115. A researcher expects that older students have a better attitude towards school, so gives the SSHA to a random sample of 25 students who are at least 30 years of age. Their average score is reported to be 127.8. Assuming the SSHA test scores are normally distributed with a standard deviation of 30, test the researchers claim.