1. In a study of how external clues influence performance, university professors gave two different forms of midterm examination to a large group of introductory students. The questions on the examwereidentical andinthesameorder,butoneexamwasprintedonbluepaperandtheother onredpaper(teachingpsychology,May1998).Gradingonlythedifficultquestionsontheexam, the researchers found that scores on the blue exam had a distribution with a mean of 53% and a standard deviation of 15%. Assume that distribution is approximately mound-shapes and symmetric. Give an interpretation of the standard deviation for the students who took the blue exam.