Question

Ashley saved money every month last year. The table below shows how much money she saved each month.

Dollars Saved

Month Money Saved (in dollars)
January 96
February 38
March 162
April 65
May 178
June 112
July 57
August 143
September 135
October 104
November 88
December 22

What is the mean absolute deviation of the amounts she saved?
A.
18
B.
156
C.
23
D.
39

Answer 1

First find the mean: (96+38+162+65+178+112+57+143+135+104+88+22) = 1200, mean = 1200/12 = 100.

Find absolute deviations from 100:
|96−100|=4, |38−100|=62, |162−100|=62, |65−100|=35, |178−100|=78,
|112−100|=12, |57−100|=43, |143−100|=43, |135−100|=35, |104−100|=4,
|88−100|=12, |22−100|=78. Sum = 468.

Mean absolute deviation = 468/12 = 39.

Answer: D.