Reference no: EM132907577

Need clarafication and answers to the following questions.

According to a recent study the lengths of human pregnancies in the U.S. are approximately normally distributed with a mean of 281 days and a standard deviation of 14 days.

a. Traditionally, it is believed that the gestation period is 40 weeks or 280 days. What is the probability that a randomly selected pregnancy in the U.S. will last longer than the traditional 40 weeks?

b. What is the probability that a random sample 10 pregnancies in the U.S. will have a mean gestation period of at least 40 weeks? How about a random sample of 20 pregnancies?

c. According to the Mayo Clinic most premature babies are born at the late preterm stage; a late preterm birth occurs when a baby is born between 34 weeks (238 days) and 37 weeks (259 days). What proportion of babies are born during this stage?

d. A very preterm baby is one born at less than 32 weeks. What is the probability that a randomly chosen birth is considered very preterm?

e. Approximately 12.5% of babies in the United States are born premature. According to this value, what would be the maximum length of pregnancy for a prematurely born baby?

f. How long are the longest 1% of pregnancies in the United States?