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If x(i)' s are the midpoints of the clas...

If `x_(i)`' s are the midpoints of the class intervals of grouped data, `f_(i)`'s are the corresponding frequencies and `barx` is the mean, then what is `Sigma (f_(i)x_(i)-barx)` equal to ?

A

0

B

-1

C

1

D

2

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