The mean of normally distributed test scores is 82 and the standard deviation is 5. If there are 153 test scores in the data sample, how many of them were in the 87 to 92 range?

Question

The options are 21, 4, 73, or 52

Answer 1

The 87 to 92 range is between 1 and 2 σ's of 5. That range on the normal distribution curve holds 13.6% of the data.

153 x .136 ≈ 21