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Question
If n = 5, Σx = Σy = 20, Σx2 = Σy2 = 90 , Σxy = 76 Find Covariance (x,y)
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Solution
Given, Σx = 20, Σy = 20, Σx2 = 90, Σy2 = 90, Σxy = 76, n = 5
Now,
`barx = (sumx)/"n" = 20/5` = 4
`bary = (sumy)/"n" = 20/5` = 4
cov(X, Y) = `1/"n" sumxy - bar(x) bar(y)`
= `1/5 xx 76 - 4 xx 4`
= 15.2 – 16
= – 0.8
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