The class mean score on a test was 60, and the standard

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The class mean score on a test was 60, and the standard deviation was 15. If Jack's score was within 2 standard deviations of the mean, what is the lowest score he could have received?

(A) 30
(B) 31
(C) 45
(D) 90
(E) 89

OA A

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by deloitte247 » Sun Aug 25, 2019 1:22 pm
Mean = 60 and standard deviation = 15.
Standard deviation from the mean = 60 - 15 = 45
This is the standard deviation below the mean.

For standard deviation above the mean = 60 + 15 = 75

Within 2 standard deviations = 15 * 2 = 30
Standard deviation below the mean = 60 - 30 = 30
Standard deviation above the mean = 60 + 30 = 90
The lowest score Jack will receive = 30 which is within 2 standard deviations of the mean.

Answer = option A

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by Scott@TargetTestPrep » Tue Aug 27, 2019 5:18 pm
BTGmoderatorDC wrote:The class mean score on a test was 60, and the standard deviation was 15. If Jack's score was within 2 standard deviations of the mean, what is the lowest score he could have received?

(A) 30
(B) 31
(C) 45
(D) 90
(E) 89

OA A

Source: GMAT Prep
Since Jack's score was within 2 standard deviations of the mean, his lowest possible score was:

60 - 2(15) = 60 - 30 = 30

Answer: A

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