The distribution of the duration of human pregnancies is approximated with a normal distribution with a mean of 266 days and a standard deviation of 16 days.
a) 10 pregnant women are selected at random. What is the probability that the average duration of these 10 pregnancies is less than 260 days?
b) If the duration of a human pregnancy is not normally distributed (in fact it is highly skewed to the left), how does this impact your answer to a?