Assume that females have pulse rates that are normally distributed with a mean of
mu equals μ=74.0 beats per minute and a standard deviation of
sigma equals σ=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 80 beats per minute.
b. if 4 adult females are randomly selected, find the probability that they have pulse rates with a mean less than 80 beats per minute.
c. why can the normal distribution be used in part (b), even though the sample size does not exceed 30?