The lengths of a particular animal's pregnancies are approximately normally distributed, with mean u = 280 days and standard deviation o = 12 days. (a) What proportion of pregnancies lasts more than 295 days? (b) What proportion of pregnancies lasts between 274 and 286 days? (c) What is the probability that a randomly selected pregnancy lasts no more than 271 days? (d) A "very preterm" baby is one whose gestation period is less than 262 days. Are very preterm babies unusual? Click the icon to view a table of areas under the normal curve. (a) The proportion of pregnancies that last more than 295 days is 10.57 (Round to four decimal places as needed.)