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

1 answer

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