Schwartz Ryan

11/09/2023 · Elementary School

The lengths of a particular animal's pregnancies are approximately normally distributed, with mean \( \mu=266 \) days and standard deviation \( \sigma=16 \) days. (a) What proportion of pregnancies lasts more than 274 days? (b) What proportion of pregnancies lasts between 242 and 270 days? (c) What is the probability that a randomly selected pregnancy lasts no more than 238 days? (d) A "very preterm" baby is one whose gestation period is less than 230 days. Are very preterm babies unusual? (a) The proportion of pregnancies that last more than 274 days is 0.3085. (Round to four decimal places as needed.) (b) The proportion of pregnancies that last between 242 and 270 days is 0.5319 . (Round to four decimal places as needed.) (c) The probability that a randomly selected pregnancy lasts no more than 238 days is 0.0401 . (Round to four decimal places as needed.) (d) The probability of a "very preterm" baby is \( \square \). This event \( \square \) unusual because the probability is \( \square \) than 0.05 .