Question

Cara is a high school student. On average, there are 26 students per class at her school, with a standard deviation of 3 students. What percentage of classes at Cara's high school will have between 20 students and 35 students?

A. 0.15%
B. 97%
C. 99%
D. 0.3%

Answer 1

B. 97%

Explanation:

20 students is -2 standard deviations away from the mean

35 is +3 standard deviations away from the mean

100 - 2.4 = 97.6

(2.4 is amount of data we are not using)

please refer to the standard deviation graph attached :)