Assume that females have pulse rates that are normally distributed with a mean of mu equals 75.0

=75.0 beats per minute and a standard deviation of sigma equals 12.5

=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 between 68

68 beats per minute and 82

82 beats per minute.

The probability is

0.4245

b. If 4 adult females are randomlyselected, find the probability that they have pulse rates with a mean between 68

68 beats per minute and 82

82 beats per minute.

The probability is

0.7373

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