SOLUTION: A set of ten numbers has a mean of 132. If one of the number is removed. The mean is now 121. What was the value of number that was removed?

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Question 1144353: A set of ten numbers has a mean of 132. If one of the number is removed. The mean is now 121. What was the value of number that was removed?
Found 2 solutions by Login@123, greenestamps:
Answer by Login@123(1) (Show Source):
You can put this solution on YOUR website!
If the mean of 10 numbers = 132
the total sum of 10 numbers= 132*10=1320
Now, let the removed number be 'a'
then total sum of left 9 numbers = 1320-a
the mean of 9 numbers = {1320-a}/9
121 = {1320-a}/9
121*9 = 1320-a
1089 = 1320-a
a = 1320-1089
a = 231
231 is the required number.

Answer by greenestamps(13203) (Show Source):
You can put this solution on YOUR website!

Each of the remaining 9 numbers is 132-121=11 below the old average; all together those 9 numbers are 9*11=99 below the old average.

So the number removed must be 99 above the old average.

ANSWER: 132+99 = 231