At one college, GPA's have a distribution that is unimodal and symmetric with a mean of 2.9 and a standard deviation of 0.6. What is the range of GPA's from one standard deviation below the mean to one standard deviation above the mean?

a) 2.3 to 2.9

b) 2.9 to 3.5

c) 0.6 to 3.5

d) 2.3 to 3.5

d) 2.3 to 3.5

Step-by-step explanation:

In this problem, we have that:

The mean is 2.9

The standard deviation is 0.6

One standard deviation below the mean

This is the mean subtracted by one standard deviation.

So this is 2.9 - 0.6 = 2.3

One standard deviation above the mean

This is one standard deviation added to the mean.

So this is 2.9 + 0.6 = 3.5

So the correct answer is:

d) 2.3 to 3.5