Question

A student is given data that follows a normal distribution. According to the data, the mean amount of time that students spent reading outside of school each month was 10 hours, and the standard deviation was 2 hours. Which percentage best represents the number of students that read between 8 and 12 hours outside of school in a month?

34%


48%


68%


96%

Answer 1

68% — because 8 and 12 are one standard deviation below and above the mean (10 ± 2), and about 68% of values in a normal distribution lie within one standard deviation (empirical rule).