The total amount being spent on personal calls in a month by employees of a company follows a
normal distribution with a mean of $900 and a standard deviation of $50. Find the probability that
in a randomly selected month the amount spent on personal calls is between $775.00 and $990.00.
Z = (score - mean)/SD
Insert the values to find the two Z scores. Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion between these Z scores.