Dean Halverson recently read that full-time college students study 20 hours each week. She decides to do a study at her university to see if there is evidence that students study an average of less than 20 hours each week. A random sample of 32 students were asked to keep a diary of their activities over a period of several weeks. It was found that he average number of hours that the 32 students studied each week was 19.1 hours. The sample standard deviation of 4.2 hours.