Assume that females have pulse rates that are normally distributed with a mean of =73.0 beats per minute and a standard deviation of =12.5 beats per minute. Complete parts(a) through(c) below.

a. If 1 adult female is randomlyselected, find the probability that her pulse rate is less than 77 beats per minute.

The probability is ______

.

(Round to four decimal places asneeded.)

b. If 25 adult females are randomlyselected, find the probability that they have pulse rates with a mean less than 77 beats per minute.

The probability is ______

.

(Round to four decimal places asneeded.)

c. Why can the normal distribution be used in part(b), even though the sample size does not exceed30?

A.

Since the distribution is of samplemeans, notindividuals, the distribution is a normal distribution for any sample size.

B.

Since the original population has a normaldistribution, the distribution of sample means is a normal distribution for any sample size.

C.

Since the mean pulse rate exceeds30, the distribution of sample means is a normal distribution for any sample size.

D.

Since the distribution is ofindividuals, not samplemeans, the distribution is a normal distribution for any sample size.