SOLUTION: The average weight for a group of 20 women is 130 pounds. If the average weight for 3/4 of these women was 140 pounds, what was the average weight, in pounds, for the rest of the w

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Question 442883: The average weight for a group of 20 women is 130 pounds. If the average weight for 3/4 of these women was 140 pounds, what was the average weight, in pounds, for the rest of the women?
Answer by Leaf W.(135) About Me  (Show Source):
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Find the average of a group by adding all the values and dividing by the number of values. Since 3/4 of a group of 20 women is 15, there are fifteen with an average of 140 pounds, and the remaining five would have an average weight of x. Therefore, 130+=+%2815%2A140+%2B+5x%29%2F20. Solve by multiplying by 20 on both sides: 2600+=+15%2A140+%2B+5x, then simplify 15%2A140: 2600+=+2100+%2B+5x, and subtract 2100 from both sides: 500+=+5x, and divide both sides by 5: 100+=+x. Therefore, the average weight for the rest of the women is 100 pounds.