Question

Assume that females have pulse rates that are normally distributed with a mean of mu equals 72.0 beats per minute and a standard deviation of sigma equals 12.5 beats per minute. Complete parts​ (a) through​ (c) below. a. If 1 adult female is randomly​ selected, find the probability that her pulse rate is less than 78 beats per minute.

The probability is ? ​(Round to four decimal places as​ needed.)

b. If 16 adult females are randomly​ selected, find the probability that they have pulse rates with a mean less than 78 beats per minute. The probability is? ​(Round to four decimal places as​ needed.)

c. Why can the normal distribution be used in part​ (b), even though the sample size does not exceed​ 30?

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

B. Since the mean pulse rate exceeds​ 30, the distribution of sample means is a normal distribution for any sample size.

C. Since the distribution is of sample​ means, not​ individuals, the distribution is a normal distribution for any sample size.

D. Since the distribution is of​ individuals, not sample​ means, the distribution is a normal distribution for any sample size

Answer 1