gmathopful wrote:

Many questions have a missing average

Example:

#Score 83 70 92 X 64

#Stdts 05 06 03 05 01

Average of 20 students is 78.

What is X?

Is there a easy of finding x ( kind of average of averages), other than multiplying individually,adding and finding out X.

There should be some simple of finding out the X.

An average of a set of averages is the weighted average sum of all the averages.

Solve for x where [(5x83)+(6x70)+(3x92)+(5xX)+(1x64)]/20 = 78

_________________

Best,

AkamaiBrah

Former Senior Instructor, Manhattan GMAT and VeritasPrep

Vice President, Midtown NYC Investment Bank, Structured Finance IT

MFE, Haas School of Business, UC Berkeley, Class of 2005

MBA, Anderson School of Management, UCLA, Class of 1993