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If a certain sample of data has a mean of 24.0 and the value 31.0 is m
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15 Oct 2021, 09:10
15 Oct 2021, 09:10
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If a certain sample of data has a mean of 24.0 and the value 31.0 is more than 2.5 standard deviations from the mean, which of the following could be the standard deviation of the sample?
(A) 3.75
(B) 3.50
(C) 3.25
(D) 3.00
(E) 2.75
(A) 3.75
(B) 3.50
(C) 3.25
(D) 3.00
(E) 2.75
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Re: If a certain sample of data has a mean of 24.0 and the value 31.0 is m
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19 Oct 2021, 11:38
19 Oct 2021, 11:38
Carcass wrote:
If a certain sample of data has a mean of 24.0 and the value 31.0 is more than 2.5 standard deviations from the mean, which of the following could be the standard deviation of the sample?
(A) 3.75
(B) 3.50
(C) 3.25
(D) 3.00
(E) 2.75
(A) 3.75
(B) 3.50
(C) 3.25
(D) 3.00
(E) 2.75
----ASIDE--------------------------
A little extra background on standard deviations above and below the mean
If, for example, a set has a standard deviation of 4, then:
1 standard deviation = 4
2 standard deviations = 8
3 standard deviations = 12
1.5 standard deviations = 6
0.25 standard deviations = 1
etc
So, if the mean of a set is 9, and the standard deviation is 4, then:
2 standard deviations ABOVE the mean = 17 [since 9 + 2(4) = 17]
1.5 standard deviations BELOW the mean = 3 [since 9 - 1.5(4) = 3]
3 standard deviations ABOVE the mean = 21 [since 9 + 3(4) = 21]
etc.
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A certain sample of data has a mean of 24.0 and the value 31.0 is more than 2.5 standard deviations from the mean
Let d = the of the standard deviation.
31 - 24 = 7
This means 7 > 2.5 standard deviations
In other words: 7 > 2.5d
Divide both sides of the inequality by 2.5 to get: 2.8 > d
Since d (the standard deviation) must be less than 2.8, the only possible answer is E
Re: If a certain sample of data has a mean of 24.0 and the value 31.0 is m
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04 Dec 2022, 03:36
04 Dec 2022, 03:36
Hello from the GRE Prep Club BumpBot!
Thanks to another GRE Prep Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).
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Thanks to another GRE Prep Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).
Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
