For a Normal Distribution Curve with a Mean of 15

Multiple Choice

For a normal distribution curve with a mean of 15 and a standard deviation of 5, which range of the variable defines an area under the curve corresponding to a probability of
Approximately 68%?

A) from 10 to 20
B) from 5 to 25
C) from 15 to 25
D) from 12.5 to 17.5