The lengths of a particular animal's pregnancies are approximately normally distributed, with mean \( \mu=257 \) days and standard deviation \( \sigma=20 \) days. (a) What proportion of pregnancies lasts more than 282 days? (b) What proportion of pregnancies lasts between 222 and 262 days? (c) What is the probability that a randomly selected pregnancy lasts no more than 232 days? (d) A "very preterm" baby is one whose gestation period is less than 212 days. Are very preterm babies unusual?

A water bottling facility has a mean bottling rate of 34.1 thousand bottles per hour with a standard deviation of 2.13 thousand bottles. A nearby cola bottling facility has a mean bottling rate of 25.7 thousand bottles per hour with a standard deviation of 1.63 thousand bottles. One Wednesday from noon to \( 1: 00 \) p.m, the water bottling facility bottled 37.2 thousand bottles of water, and the cola bottling facility bottled 27.7 thousand bottles of cola. Which facility increased their efficiency more during that hour? Answer

A water bottling facility has a mean bottling rate of 34.1 thousand bottles per hour with a standard deviation of 2.13 thousand bottles. A nearby cola bottling facility has a mean bottling rate of 25.7 thousand bottles per hour with a standard deviation of 1.63 thousand bottles. One Wednesday from noon to \( 1: 00 \) p.m., the water bottling facility bottled 37.2 thousand bottles of water, and the cola bottling facility bottled 27.7 thousand bottles of cola. Which facility increased their efficiency more during that hour? Answer

The grades on the second statistics test for Mr. Brown's class are in the following list. Find the frequency distribution for the grades. \[ \text { C, D, B, F, B, A, F, F, B, B, B, F, D, B, F, D, F, B, F, B, C } \]

The grades on the second statistics test for Mr. Brown's class are in the following list. Find the frequency distribution for the grades. \[ F, C, B, D, D, A, F, B, B, D, F, D, D, B, B, D, B, A, D, F, D \]

Scores on a test have a mean of 89 and a standard deviation of 7 . Calvin has a score of 79. Convert Calvin's score to a \( z \)-score, rounded to the nearest hundredth.