math 540
posted by renee .
suppose it takes a college student an average of 5 minutes to find a parking space on the schools parking lot. Assume also that this time is normally distributed with a standard deviation of 2 minutes. What time is exceeded by approximately 75% of the college students when trying to find a parking spot in the main parking lot?Answer 3.7 minutes

from your Z table, 25% of the area means 0.674 std below the mean.
That means 5  .674(2) = 3.65 which rounds to 3.7
Make a visit to
http://davidmlane.com/hyperstat/z_table.html
to play around with Z table stuff