Assume the duration of human pregnancies can be described by a normal model with mean 263 days and standard deviation 11 days. Suppose a certain obstetrician is currently providing prenatal care to 40 pregnant women. Let x̄ represent the mean length of their pregnancies.a) According to the Central Limit Theorem, what is the mean and standard deviation of x̄?b) What is the probability that the mean duration of these patients' pregnancies will be less that 258 days?