Question

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

One standard deviation above the mean comprises 34% of the normal distribution. The same is true for one standard deviation below the mean. The range is (2.2, 3.2), and since the mean is 2.7 and the SD 0.5, this means the range covers the range from SD = -1 to SD = 1.

34% + 34% = 68%