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.
A and B are graphical representations of normally distribute
[#permalink]
30 Jul 2018, 09:06
30 Jul 2018, 09:06
1
Expert Reply
6
Bookmarks
00:00
Question Stats:
55% (00:46) correct
44% (00:45) wrong based on 87 sessions
Hide Show timer Statistics
Attachment:
#GREpracticequestion A and B are graphical representations of normally.PNG [ 79.62 KiB | Viewed 8034 times ]
A and B are graphical representations of normally distributed random variables X and Y, respectively, with relative positions, shapes, and sizes as shown. Which of the following must be true?
Indicate all such statements.
A. Y has a greater standard deviation than X.
B. The probability that Y falls within 2 standard deviations of its mean is greater than the probability that X falls within 2 standard deviations of its mean.
C. Y has a greater mean than X.
Re: A and B are graphical representations of normally distribute
[#permalink]
23 Aug 2018, 09:22
23 Aug 2018, 09:22
2
The dataset in B is more flat than A so S.D of B> S.D of A
Probability range for all SD in a normal distribution is fixed at 34%, 14% and 2% above and below the mean for 1st, 2nd and 3rd SD
The value directly beneath the protruded part of the curve is the mean. Clearly from the two graphs mean of y>mean of x
Posted from my mobile device
Probability range for all SD in a normal distribution is fixed at 34%, 14% and 2% above and below the mean for 1st, 2nd and 3rd SD
The value directly beneath the protruded part of the curve is the mean. Clearly from the two graphs mean of y>mean of x
Posted from my mobile device
Re: A and B are graphical representations of normally distribute
[#permalink]
13 Jun 2019, 07:51
13 Jun 2019, 07:51
amorphous wrote:
The dataset in B is more flat than A so S.D of B> S.D of A
Probability range for all SD in a normal distribution is fixed at 34%, 14% and 2% above and below the mean for 1st, 2nd and 3rd SD
The value directly beneath the protruded part of the curve is the mean. Clearly from the two graphs mean of y>mean of x
Posted from my mobile device
Probability range for all SD in a normal distribution is fixed at 34%, 14% and 2% above and below the mean for 1st, 2nd and 3rd SD
The value directly beneath the protruded part of the curve is the mean. Clearly from the two graphs mean of y>mean of x
Posted from my mobile device
------------------------------
Need little more explication of the option C:
Flatter graph has highly dispersed data while the narrower one is not- meaning most of its values are centred around the mean.If the values has low dispersion, then they must have a mean closer to centralised values. But the highly dispersed values pull down the mean (?),therefore small mean.
Is the above correct ?
