GRE Prep Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
After preparing the results of their measurement of the
[#permalink]
09 Dec 2017, 19:24
09 Dec 2017, 19:24
Expert Reply
2
Bookmarks
00:00
Question Stats:
52% (02:46) correct
48% (02:36) wrong based on 25 sessions
Hide Show timer Statistics
After preparing the results of their measurement of the weight of children that participated in their pediatric study, Steph’s graduate assistant spilled coffee on their papers. If Steph is able to read that 50 lbs is the third standard deviation to the left of the mean, and 110 lbs also falls on a standard deviation, then which of the following could be the mean weight of the children in the study, assuming regular distribution?
Indicate all possible values.
A. 80
B. 85
C. 86
D. 95
E. 100
Indicate all possible values.
A. 80
B. 85
C. 86
D. 95
E. 100
Show: :: OA
A, C, D
Drill 4
Question: 1
Page: 531
Question: 1
Page: 531
Re: After preparing the results of their measurement of the
[#permalink]
29 Dec 2017, 15:35
29 Dec 2017, 15:35
2
Expert Reply
Explanation
Draw a bell curve with three standard deviations to the left and the right of mean.
Plug in 50 lbs on the leftmost standard deviation as mentioned in the question. Start with choice (A), plug in 80 lbs for the mean, and solve for the standard deviation. In this case it would be 10, and it’s possible to see that 110 would be the third standard deviation to the right of the mean.
Therefore, choice (A) satisfies the question. If you repeat this with choice (B), you’ll find that the standard deviation would have to be 11.67. Thus, the value two standard deviations to the right of the mean is 108, and is just shy of what you want.
In choice (C), the mean is 86, the standard deviation is 12, and 110 will be the second deviation to the right of the mean.
Choice (D) works; the mean is 95, standard deviation is 15, and 120 is the first value to the right of the mean. You can Ballpark to eliminate choice (E). Its standard deviation is about 16, and the first standard deviation to the right would be about 116, which means 110 cannot fall on a standard deviation.
Draw a bell curve with three standard deviations to the left and the right of mean.
Plug in 50 lbs on the leftmost standard deviation as mentioned in the question. Start with choice (A), plug in 80 lbs for the mean, and solve for the standard deviation. In this case it would be 10, and it’s possible to see that 110 would be the third standard deviation to the right of the mean.
Therefore, choice (A) satisfies the question. If you repeat this with choice (B), you’ll find that the standard deviation would have to be 11.67. Thus, the value two standard deviations to the right of the mean is 108, and is just shy of what you want.
In choice (C), the mean is 86, the standard deviation is 12, and 110 will be the second deviation to the right of the mean.
Choice (D) works; the mean is 95, standard deviation is 15, and 120 is the first value to the right of the mean. You can Ballpark to eliminate choice (E). Its standard deviation is about 16, and the first standard deviation to the right would be about 116, which means 110 cannot fall on a standard deviation.
Re: After preparing the results of their measurement of the
[#permalink]
28 Sep 2019, 05:54
28 Sep 2019, 05:54
""110 lbs also falls on a standard deviation""............. If you Understand This, The problem will be easy to solve. It does not mean that 110 is within 1 standard deviation. It just says that 110 is in a standard deviation point, it may be 1 SD, 2 SD etc. So, It is better to combat this math with the answers given.
