A new phone system was installed last year to help reduce the expense of personal calls that were being made by employees. Before the new system was installed, the amount being spent on personal calls follows a normal distribution with an average of $400 per month and a standard deviation of $50 per month. Refer to such expenses as PCE's .

Find the point in the distribution below which 2.5% of the PCE's fell.

a. $302

b. $10

c. $390

d. $498