Suppose that the amount of time that shoppers wait in line to enter a store is normally distributed with a mean of 70 mins and a standard deviation of 5 mins. If 25 shoppers are randomly, find the...

Suppose that the amount of time that shoppers wait
in line to enter a store is normally distributed with a
mean of 70 mins and a standard deviation of 5 mins.
If 25 shoppers are randomly, find the probability
that their average wait time:
a) Below 71 mins
b) More than 68.5 mins
c) Between 69 mins and 72 mins