Source: Official Guide Revised GRE 1st Ed. Part 8; Section 5; #8


A random variable Y is normally distributed

A random variable Y is normally distributed with a mean of 200 and a standard deviation of 10. Quantity A : The probability of the event that the value of Y is greater than 220 Quantity B : 1/6 Quantity A is greater., Quantity B is greater., The two quantities are equal., The relationship cannot be determined from the information given.

3 Explanations


Newaz Sharif

It will be at number 9, there is little back and in number of math and so confused.

Nov 4, 2015 • Comment

Cydney Seigerman, Magoosh Tutor

Thanks for letting us know, Tuhin! I've made a note to our content editors that this question and video correspond to #9 of the OG, so that this can be fixed :) Thanks again!

Nov 11, 2015 • Reply


where can i find the complete qustions for these videos

Aug 21, 2015 • Comment

Jonathan , Magoosh Tutor

These questions are from the Official Guide to the Revised GRE, which is published by ETS. We recommend including this source in your GRE preparation.

Aug 31, 2015 • Reply


Gravatar Chris Lele, Magoosh Tutor

Oct 11, 2012 • Comment

Juby Varghese

How did we get 34 and 13 percents?

Jul 5, 2013 • Reply

Kevin Rocci, Magoosh Tutor

Hi Juby,

Basic knowledge of Standard Deviation is something that you will need to know for GRE Quant. The percents that Chris talks about in the video are part of the foundational knowledge that you will need for the test.

To learn more about standard deviation, I recommend reading through these resources. They will explain the concept and talk about where these percents come from.

I hope that this helps!

Jul 23, 2013 • Reply

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