Please answer question D.

Assume that the duration of human pregnancies can be described by a normal model with mean 267 days and standard deviation 14 days. Complete parts a) through d) below. a) What percentage of pregnancies should last between 265 and 280 days? 38.0 % (Round to one decimal place as needed.) b) At least how many days should the longest 30% of all pregnancies last? P(X2 274.3 ) = 0.30 (Round to one decimal place as needed.) c) Suppose a certain obstetrician is currently providing prenatal care to 50 pregnant women. Let y represent the mean length of their pregnancies. According to the central limit theorem, what is the mean and standard deviation SD(y) of the normal model of the distribution of the sample mean, y? The mean is 267 . SD(y) = 1.98 (Round to two decimal places as needed.) d) What is the probability that the mean duration of these patients' pregnancies will be less than 270 days? P(y