PS Practice test question #5

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PS Practice test question #5

by missionmba » Sat Aug 16, 2008 1:29 am
Teacher
Average for Male Students
Average for Female Students
Average for All Students

Mr. Anderson
83
91
88

Ms. Baker
87
83
85

Mr. Chavez
93
90
92

Ms. Do
91
86
89



The chart above gives the average (arithmetic mean) of the results, broken down by class and gender, of a graduation test administered to 12th graders at Central High School. If all students have taken the test, how many of the 12th grade classes have more female students than male students?


1

2

3

4

It cannot be determined from the information given.
Mission Mba

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by pepeprepa » Sat Aug 16, 2008 1:50 am
You build equations with information
For the first one:
X: Men
Y: Women
(83/100)X + (91/100)Y=88/100(X+Y)
83X+91Y=88X + 88Y
3Y=5X
Y=(5/3)X

So Y>X
There are more women than men in the first class.

And for each of the classes

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by arorag » Sat Aug 16, 2008 9:21 am
I think here thy are testing the concept of weighted average.

Take class 1--- equal no. of male and female then average= 67 but given average is 88 so get 88 you need more high value no. which are in this case female