I'm not math savy anymore. Can anybody tell me why the answer to this problem is 100?

"Five pieces of wood have an average (arithmetic mean) lenth of 124 cm and a median length of 140 cm. What is the maximum possible lenth in centimeters, of the shortest piece of wood?"

90 / 100 / 110 / 130 / 140

I know the answer is 100 but I don't know why thats the case......

7/27/2008 10:29:46 PM

Isn't the median 110, not 140?

7/27/2008 10:48:34 PM

Sorry... 90 / 100 / 110 / 130 / 140 were the possible choices and 100 was the correct answer.

7/27/2008 11:34:48 PM

wow... how did you get into state ?
Major : Aerospace Engineering ??? no way.



the median is 140 and the average is 124


so xxx xxx 140 xxx xxx ....... the last two have to be greater or equal to 140 since its the median. assuming the last two are 140 ( because you're trying to get the max length of the shortest piece so it would only make sense to make these equal to the median or else you would end with a shorter ( short ) piece of wood ) 140*3 = 420 ..... now this is where you use reasoning to pick a number and try it out. For your case lets try out 110 so ( 110*2 + 140*3 )/5 ...... equals 128 .... so the average for this scenario doesnt meet the requirements so 110 is not the answer.

100 works out to be an average of 124..... so 100 is the max.


100 is your answer.

[Edited on July 27, 2008 at 11:47 PM. Reason : x]

[Edited on July 27, 2008 at 11:48 PM. Reason : x ]

7/27/2008 11:45:53 PM

guess and check is very necessary here.

7/28/2008 12:05:21 AM

Thanks for the help!


and as expected... Sarcasam in responses is about the same when I was State haha


Holla 2005 Grads!

7/28/2008 7:50:00 PM