SOLUTION: 1. [4 pts] The average weight of 6 people in an elevator is 173 pounds. A 7th person gets on and now the average weight is 165 pounds. How much did the 7th person weigh?

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Question 1125829: 1. [4 pts] The average weight of 6 people in an elevator is 173 pounds. A 7th
person gets on and now the average weight is 165 pounds. How much
did the 7th person weigh?
Answer by greenestamps(13200) (Show Source):
You can put this solution on YOUR website!

The average of all 7 people is the total weight of the original 6 people, plus the weight of the 7th person, all divided by 7. Algebraically....

The average weight is now 165; so solve the equation

I'll let you finish....

For problems like this involving an average of numbers that are "close" together, here is a different strategy for solving the problem that you might like to try.

The original 6 people have an average weight of 173, which is 8 pounds more than the average of all 7 people. So all together, the weight of those 6 people is 6*8=48 pounds over the 165 average. That means the 7th person's weight must be 48 pounds below the 165 average.

So the weight of the 7th person is 165-48 = 117 pounds.