kaplan average problem

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kaplan average problem

by pradeepkaushal9518 » Tue May 04, 2010 7:32 am
monday $75.38
tuesday $ 75.63
wednesday $75.42
thursday $ 75.52
friday

the table above shows the closing price of a stock during a week. if the average closing price for the five days was $75.50, what was the closing price on friday?
kindly solve without using the traditional way.

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by debmalya_dutta » Tue May 04, 2010 7:36 am
Total =75.5*5
5th day closing price = (75.5*5) - (75.38+75.63+75.42+75.52) = 75.55

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by ssuarezo » Tue May 04, 2010 7:40 am
debmalya_dutta wrote:Total =75.5*5
5th day closing price = (75.5*5) - (75.38+75.63+75.42+75.52) = 75.55
Clear explanation. No need to redo it.
Rate: Easy.

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by pradeepkaushal9518 » Tue May 04, 2010 7:57 am
sorry dudes its not the correct answer and its the traditional way only any body else

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by ssuarezo » Tue May 04, 2010 8:55 am
pradeepkaushal9518 wrote:sorry dudes its not the correct answer and its the traditional way only any body else
Pradeep,
Either traditional or not, we should get the same answers. it's an average question (unless stock pricing works diferently), so no mystery on it with new formulas. By the way, I dont know what it would be non traditional without being harder as, as far as I know, this is the simplest way to solve average problems.

Would u solve it with some of your non-traditional examples?

Thanks
Silvia

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by pradeepkaushal9518 » Tue May 04, 2010 9:15 am
sorry there is one mistake the monday closing is 75.58 in place of 75.38.
you will get the correct answer. but by this method we have to do a lots of calculation that is traditional way.

monday 75.58 average +0.08
tuesday 75.63 average+0.13
wednesday 75.42 average -0.08
thursday 75.52 average+0.02
after 4 days average +0.15

to make the values balance out the fifth day must be ( average-0.15) or 75.35

i expect this method as it contains less calculations

thanks silvia for your repsonse

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by frank1 » Tue May 04, 2010 9:34 am
i was astonished to know difference method yeilds different answers
but seems like it is not the case
any way if i were to do this in real gmat
i think i would do

thinking:the answer is 75.xx
now
(0.5*5) - (0.38+0.63+0.42+0.52) = 0.55
that addition seems long but it can be done at once and is manageble inside 2 minutes i guess...
i think in non traditional way you described,the problem is final average of 4 numbers
(if just addition can do why to derive average plus you are substracting each value individually as well)

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by harshavardhanc » Tue May 04, 2010 10:24 am
pradeepkaushal9518 wrote:
monday $75.58
tuesday $ 75.63
wednesday $75.42
thursday $ 75.52
friday ?

Avg for 5 days : 75.50
4 days surplus is [ +(.08) + (.13) - (.08) + (.02) ] = .15

so the fifth day should be .15 less than the avg. i.e 75.35 .
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Harsha

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by kstv » Tue May 04, 2010 4:48 pm
pradeepkaushal9518 wrote:sorry there is one mistake the monday closing is 75.58 in place of 75.38.
you will get the correct answer. but by this method we have to do a lots of calculation that is traditional way.
monday 75.58 average +0.08
tuesday 75.63 average+0.13
wednesday 75.42 average -0.08
thursday 75.52 average+0.02
after 4 days average +0.15
to make the values balance out the fifth day must be ( average-0.15) or 75.35
i expect this method as it contains less calculations
thanks silvia for your repsonse
what were the answer options, if so please post them ?