18.18 page 328 (a) One of the things that the sampling distribution of p-hat in
this problem tells us is that the proportion of students that apply to at least one more
college other than the one they are in is between 32% to 38%.( mean + or - three
standard deviations).

18-18 (d) P(p-hat < 0.33 or p-hat > 0.35)  = P(p-hat < 0.33) + P(p-hat > 0.35) = 0.025 from (c)
          plus 0.5, because the second term is the right side of the mean in the bell curve = 0.525.