a. The mean diastolic blood pressure level for adult women is 67.4, with a standard deviation of 11.6 (based on Data Set 1 in Appendix B). Using the range rule of thumb, would a diastolic blood pressure of 38 be considered unusual? Explain.

b. A student, who rarely attends class and does no homework, takes a difficult true/false quiz consisting of 10 questions. He tells the instructor that he made random guesses for all answers, but he gets a perfect score. What is the probability of getting all 10 answers correct if he really does make random guesses? Is it unusual to get a perfect score on such a test, assuming that all answers are random guesses?