2. The length of pregnancies is normally distributed with a mean of 269 days and a standard deviation of 15 days. a. What is the probability that a randomly chosen pregnancy will be longer than 274 days? (4pts) b. A baby is considered premature if the length of pregnancy is in the lowest 3.5%. Find the length of pregnancy that separates premature babies from those who are not premature. (5pts) c. What is the probability that the mean pregnancy length of 30 women will be between 260 and 270 days? (6pts) 3. A survey of 250 CSM students found 80 of them smoked. Assume CSM and Canada are relatively similar. If you want to be 98% confident that you would obtain the percentage of Canada students that smoke with a margin of error of 2.5%, find the minimum sample size needed for your survey. (6pts)