Assume that the distribution of the duration of human pregnancies has a normal distribution with a mean of 266 days and a standard deviation of 16 days.
a) 500 pregnant women are selected at random. Let N be the number of pregnancies in the sample with a duration between 260 and 280 days. Find P(200 ??≤?? N ??≤?? 300) and P(N = 265)