x1 = weight of the first piece
x2 = weight of the secound piece
x3 = weight of the third piece
x4 = weight of the fourth piece ( extra piece )
Average weight of first three pieces:
( x1 + x2 + x3 ) / 3 = m
Multiply both sides by 3
x1 + x2 + x3 = 3 m
Average weight of four pieces:
( x1 + x2 + x3 + x4 ) / 4 = 2 m
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Remark:
( x1 + x2 + x3 = 3 m )
so:
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( 3 m + x4 ) / 4 = 2 m
Multiply both sides by 4
3 m + x4 = 8 m
Subtract 3 m to both sides
3 m + x4 - 3 m = 8 m - 3 m
x4 = 5 m
The weight of the extra piece = 5 m
Three pieces of fruit have an average weight of m grams. After another piece of fruit is added, the average weight doubles. Find the weight of the extra piece of fruit in terms of m.
1 answer