One indicator of the level of economic hardship is the number of people who bring items to a pawnbroker. Assume that the number of people bringing items to a pawnshop per day in is normally distributed with a mean of 658. 

a. Suppose you learn that on 3% of the days, 610 or fewer people brought items to the pawnshop. What is the standard deviation of the number of people bringing items to the pawnshop per day? 

b. On any given day, what is the probability that between 600 and 700 people bring items to the pawnshop? 

c. How many people bring items to the pawnshop on the busiest 3% of days?