For a study in a State University Hospital, 3856 pregnant women who reported information on length of gestation until birth had mean = 284 days and standard deviation

= 12 days. A baby is classified as premature if the gestation time is 258 days or less.

(a) If mothers’ gestation times are normally distributed, what proportion of babies would be born prematurely?

(b) The actual proportion born prematurely during this period was 0.045.

Based on this information, how would you expect the distribution of gestation time to differ from the normal distribution?