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How many maple trees had a diameter greater than 49.4 cm ?
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17 May 2021, 14:02
17 May 2021, 14:02
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65% (01:15) correct
35% (01:27) wrong based on 20 sessions
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How many maple trees had a diameter greater than 49.4 cm ?
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Senior Manager
Joined: 23 Jan 2021
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Concentration: , International Business
Re: How many maple trees had a diameter greater than 49.4 cm ?
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21 May 2021, 02:03
21 May 2021, 02:03
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We know standard deviation curve has divided into 34%,14%, and 2% both in left and right with increment in each unit above or below the standard deviation. Here average is provided 42 and adding one unit above S.D. is 49.4 and left with (14+2)%. hence ans is 16% of 50=8.
hope it helps.
hope it helps.
Retired Moderator
Joined: 19 Nov 2020
Posts: 326
Given Kudos: 64
GRE 1: Q160 V152
How many maple trees had a diameter greater than 49.4 cm ?
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21 Aug 2021, 08:07
21 Aug 2021, 08:07
2
Actually when data is skewed, interquartile range and median are better parameters of descriptive stats than mean and variation. IMO, this question is missing a point about normal distribution. Hence, the assumption about normal distribution is the only way to solve it. Otherwise, there is no way to establish a link between mean and standard deviation. For normal distribution though, when we divide the difference between a mean and any variable by a standard deviation we get the standard normal distribution with mean=0 and standard deviation=1
Because that is the only Distribution asked by ETS in GRE
KarunMendiratta wrote:
greenmonomer wrote:
why did you consider it as normal distribution?
Because that is the only Distribution asked by ETS in GRE
