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If the mean of list A is 6.8 and the standard deviation is

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by Gmat_mission » Sun May 05, 2019 10:58 am

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Answers

A

B

C

D

E

Stats

Difficulty—

If the mean of list A is 6.8 and the standard deviation is 3.6, then how many elements of list A are within 1 unit of standard deviation of the mean?

A = {2, 9, 2, 6, 9, 10, 7, 4, 5, 14}

A. 3
B. 4
C. 5
D. 6
E. 7

[spoiler]OA=E[/spoiler]

Source: Magoosh
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by Jay@ManhattanReview » Mon May 06, 2019 12:01 am
Gmat_mission wrote:If the mean of list A is 6.8 and the standard deviation is 3.6, then how many elements of list A are within 1 unit of standard deviation of the mean?

A = {2, 9, 2, 6, 9, 10, 7, 4, 5, 14}

A. 3
B. 4
C. 5
D. 6
E. 7

[spoiler]OA=E[/spoiler]

Source: Magoosh
The range for elements within 1 unit of standard deviation is given by (6.8 - 3.6) - (6.8 + 3.6) => 3.2 - 10.4

The elements within 3.2 - 10.4 range are 9, 6, 9, 10, 7, 4, and 5. There are 7 elements.

The correct answer: E

Hope this helps!

-Jay
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by Scott@TargetTestPrep » Thu May 09, 2019 5:11 pm
Gmat_mission wrote:If the mean of list A is 6.8 and the standard deviation is 3.6, then how many elements of list A are within 1 unit of standard deviation of the mean?

A = {2, 9, 2, 6, 9, 10, 7, 4, 5, 14}

A. 3
B. 4
C. 5
D. 6
E. 7

[spoiler]OA=E[/spoiler]

Source: Magoosh

One standard deviation above the mean is 6.8 + 3.6 = 10.4, and one standard deviation below the mean is 6.8 - 3.6 = 3.2.

Thus, we see that there are 7 elements (9, 6, 9, 10, 7, 4, 5) within one standard deviation of the mean.

Answer: E

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