Re: a statistic question -- 會考加油站

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Subject: Re: a statistic question

Author:
ipl

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Date Posted: 10:34:15 04/27/03 Sun
In reply to: xpoon 's message, "a statistic question" on 00:22:44 04/04/03 Fri

Too easy!!!!!
First, standard deviation indicate dispersion, a represent the level of dispersion,ie the larger the a, the larger the dispersion. eg:1,2,3 are multiplied by 2, range will go from 2 to 4 (2,4,6), standard deviation will double also.In your question, standard deviation go from 10 to 15, it is multiplied by 1.5, it means that all the score is multiplied by 1.5 that's why a=1.5.After the multiplication, mean will be multiplied by 1.5 also, eg mean of 1,2,3 is 2,After the multiplication of 1.5, new mean is 3 (1.5,3,4.5), new mean become 75 in your question, but it said the mean is 60, therefore b=-15
(75-60=15).
This question is easier wow!!!!!

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Replies:

Subject	Author	Date
Thanks	xpoon	06:43:54 04/30/03 Wed