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PS  Median [#permalink]
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04 Oct 2008, 10:09
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I don't understand this q. What does this question mean???
Amount earned per day($) : 96 / 84 / 80 / 70 / 48 Number of days : 4 / 7 / 4 / 3 / 2
A student worked for 20 days. For each of the amount shown in the first row of the table, the second row gives the number of days that the student earned that amout. What is the mean amount of the money that the student earned per day for the 20 days?
1. $96 2. $84 3. $80 4. $70 5. $48



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Re: PS  Median [#permalink]
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04 Oct 2008, 12:28
Your thread title is misleading. The question asks for the mean (average), not the median.
I assume you know how to find a basic average by adding up the numbers and then dividing by the number of numbers.
This question is the same, but it's written a little differently. Instead of explicitly stating all the numbers in the set, it puts them in "categories."
So there are 4 96's, 7 84's, 4 80's, 3 70's, and 2 48's
4*96 + 7*84 + 4*80 + 3*70 + 2*48 = 1598
There are 20 total numbers. This is given in the problem, or you could add 4 + 7 + 4 + 3 + 2 = 20
So divide 1598 by 20 and you get 79.9, which rounds to 80.



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Re: PS  Median [#permalink]
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04 Oct 2008, 12:55
csvobo wrote: Your thread title is misleading. The question asks for the mean (average), not the median.
I assume you know how to find a basic average by adding up the numbers and then dividing by the number of numbers.
This question is the same, but it's written a little differently. Instead of explicitly stating all the numbers in the set, it puts them in "categories."
So there are 4 96's, 7 84's, 4 80's, 3 70's, and 2 48's
4*96 + 7*84 + 4*80 + 3*70 + 2*48 = 1598
There are 20 total numbers. This is given in the problem, or you could add 4 + 7 + 4 + 3 + 2 = 20
So divide 1598 by 20 and you get 79.9, which rounds to 80. Don't look like a GMAT question



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Re: PS  Median [#permalink]
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04 Oct 2008, 17:49
This question as well is from GMATPrep (1st). And the answer is not $80, which made me disappointed...



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Re: PS  Median [#permalink]
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04 Oct 2008, 20:33
This is very much a GMAT type question. GMAT loves this question category  weighted average.
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Re: PS  Median [#permalink]
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04 Oct 2008, 23:14
Richardson wrote: This question as well is from GMATPrep (1st). And the answer is not $80, which made me disappointed... I wionder whats 79.9 equivalent to then ... Is there any hidden trick in the question ??????
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Re: PS  Median [#permalink]
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04 Oct 2008, 23:47
I read the responses of everybdy, posted till now ! Okay if we go with th equestion and Mean has to calculate, every bdy is right Mean is 79.9 Around $80.
But if we go with the Question title, means calculate the Median. Than arrange all 20 days wages in to the ascending order. Means 48, 48, 70,70,70, 80, 80, 80, 80, 84, 84, 84, 84, 84, 84, 84, 96, 96, 96, 96 So 10th & 11th term is 84 and mean of this is 84. Means Median is 84.
Now its upto question what it asks. Please share the official Answer!



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Re: PS  Median [#permalink]
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05 Oct 2008, 00:25
Richardson wrote: I don't understand this q. What does this question mean???
Amount earned per day($) : 96 / 84 / 80 / 70 / 48 Number of days : 4 / 7 / 4 / 3 / 2
A student worked for 20 days. For each of the amount shown in the first row of the table, the second row gives the number of days that the student earned that amout. What is the mean amount of the money that the student earned per day for the 20 days?
1. $96 2. $84 3. $80 4. $70 5. $48 = 96x.2 + 84x.35 + 80x.2 + 70x.15 + 48x.1 = 19.2 + 29.4 + 16 + 10.5 + 4.8 = 79.9 so mean = 79.90 median = 84 make sure you got the correct question. Largly, GMATPREP questions cannot be worng.
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Re: PS  Median [#permalink]
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05 Oct 2008, 07:49
AmitGUPTA wrote: I read the responses of everybdy, posted till now ! Okay if we go with th equestion and Mean has to calculate, every bdy is right Mean is 79.9 Around $80.
But if we go with the Question title, means calculate the Median. Than arrange all 20 days wages in to the ascending order. Means 48, 48, 70,70,70, 80, 80, 80, 80, 84, 84, 84, 84, 84, 84, 84, 96, 96, 96, 96 So 10th & 11th term is 84 and mean of this is 84. Means Median is 84.
Now its upto question what it asks. Please share the official Answer! Yes. OA given is $84. THanks. Is it the only way to solve this kind of Q?



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Re: PS  Median [#permalink]
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05 Oct 2008, 11:05
Richardson wrote: Yes. OA given is $84. THanks. Is it the only way to solve this kind of Q?
If the question asked for median, then it is simple. Data given in the question is in the descending order anyways. Now, since there are 20 days, median value will be the average of 10th and 11th day $ amount that is $84. Hence, median will be $84.



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Re: PS  Median [#permalink]
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05 Oct 2008, 11:46
scthakur wrote: Richardson wrote: Yes. OA given is $84. THanks. Is it the only way to solve this kind of Q?
If the question asked for median, then it is simple. Data given in the question is in the descending order anyways. Now, since there are 20 days, median value will be the average of 10th and 11th day $ amount that is $84. Hence, median will be $84. exactly the way i did
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