20. For 5459 pregnant women using Aarhus University Hospital in Denmark in a two-year period who reported information on length of gestation until birth, the mean was 2819 days. with standard deviation 114 days. A baby is classified as premature if the gestation ume is 258 days or less (British Medical Journal. Vol 307, July 24, 1993. p. 234).

a) If gestation times we normally distributed, what proportion of babies would be horn prematurely

b) The actual proportion bora prematurely during this period was 036 Based on this in- formation, how would you expect the distribution of gestation time to differ from normal"