Assume that females have pulse rates that are normally distributed with a mean of mu equals 74.0μ=74.0 beats per minute and a standard deviation of sigma equals 12.5σ=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 7777 beats per minute.   The probability is nothing. ​(Round to four decimal places as​ needed.) b. If 1616 adult females are randomly​ selected, find the probability that they have pulse rates with a mean less than 7777 beats per minute.   The probability is nothing. ​(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 distribution is of sample​ means, not​ individuals, the distribution is a normal distribution for any sample size.   B. Since the distribution is of​ individuals, not sample​ means, the distribution is a normal distribution for any sample size.   C. Since the mean pulse rate exceeds​ 30, the distribution of sample means is a normal distribution for any sample size.   D. Since the original population has a normal​ distribution, the distribution of sample means is a normal distribution for any sample size.

Definition Definition Number of subjects or observations included in a study. A large sample size typically provides more reliable results and better representation of the population. As sample size and width of confidence interval are inversely related, if the sample size is increased, the width of the confidence interval decreases.