Assume that females have pulse rates that are normally distributed with a mean of μ= 75.0 beats per minute and a standard deviation of σ= 12.5 beats per minute. Part A- If 1 adult female is randomly​ selected, find the probability that her pulse rate is less than 82 beats per minute.
ALREADY COMPLETED, probability 0.7123

Part B- If 4 adult females are randomly​ selected, find the probability that they have pulse rates with a mean less than 82 beats per minute.
NOT COMPLETED, need probability!!

Any help would be appreciated. Thank you so much