Column A On a recent test, a math class had an average score of 71. The ... ...
| Column A |
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Column B |
| The number of boys who took the test |
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The number of girls who took the test |
(A) Column A is larger
(B) ...
(C) ...
(D) ...
(E) ...
*This question is included in
Nova Math - Problem Set Q: Averages
Replies to This Thread: 1
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Column A On a recent test, a math class had an average score of 71. The ... ...
Posted: 07/31/2013 13:23
I remember I solved a question like this one and the answer was D, because we have no clue about the number of boys, they could be more than gurls,
Three boys made 90, 40, 50 so the average is 60
Two girls made 80, 80 average is 80
So In this case boys are more, we can add score as much as we want, that's will not make us sure about the number of boys/girls who have the test,
Please correct me if I'm wrong, my test next week That's why I'm putting some comments those days, sorry for inconvenience!
Admin
Reply 1 of 1
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Posted: 07/31/2013 14:16
Hi Sudad,
In your example, you calculated the averages for the boys and girls separately. But you did not calculate the average for the whole class, which is a 'weighted' average and therefore will be closer to the boys' average than the girls' average because you selected more boys (3) than girls (2). To calculate the average score for the whole class, we add up the five scores and divide by 5:
(90 + 40 + 50 + 80 + 80)/5 = 340/5 = 68
Notice that 68 is smaller than the 71 class average in the problem and that 68 is closer to the boys' average (60) than the girls' average (80).
Nova Press
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Column A On a recent test, a math class had an average score of 71. The ... ...
Posted: 07/27/2016 09:36
Hello- is there a way to know exactly how many boys and how many girls took the test with the information given?
