At one college, GPA's are normally distributed with a mean of 2.7 and a standard deviation of 0.5. What percentage of students at the college have a GPA between 2.2 and 3.2?

Answer 1

Z = (score-mean)/SD

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability between the two Z scores.

This is simple enough that the approximation could be memorized.

Answer 2

68

Answer 3

68%