3. Critical Thinking For a binomial probability distribution, it is unusual for the number of successes to be less than m  2.5s or greater than m 1 2.5s.

(a) For a binomial experiment with 10 trials for which the probability of success on a single trial is 0.2, is it unusual to have more than five successes? Explain.

(b) If you were simply guessing on a multiple-choice exam consisting of 10 questions with 5 possible responses for each question, would you be likely to get more than half of the questions correct? Explain.