The scores of an examination are normally distributed with a mean of 500 and standard deviation of 100. If a student is selected at random, find the probability that a student scored below 600.

Answer 1

The normal distribution has 50% on each side of the mean. The first standard deviation (from 500 to 600) has 34.1% of the total. So just add 50% and 34.1% to get 84.1%