Question

When Mrs. Myles gave a test, the scores were normally distributed with a mean of 72 and a standard deviation of 8. This means that 95% of her students scored between which two scores?

A) 40 and 100
B) 48 and 96
C) 56 and 88
D) 64 and 80

Answer 1

Point blank the answer is C

Explanation:

In a normal distribution, 95% of the data lies within two standard deviations of the mean. Add and subtract 8 to and from 72 twice and the correct answer is between 56 and 88.

Answer 2

95% CI = 72 + or - 1.96(8) = 72 + or - 15.68 = 56.32 to 87.68 ≈ 56 to 88.
Option is is the correct answer.