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Question
Compute the product moment coefficient of correlation for the following data:
n = 100, `bar x` = 62, `bary` = 53, `sigma_x` = 10, `sigma_y` = 12
`Sigma (x_i - bar x) (y_i - bary) = 8000`
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Solution
Given : n = 100, `bar x` = 62, `bary` = 53, `sigma_x` = 10, `sigma_y` = 12
`Sigma (x_i - bar x) (y_i - bary) = 8000`
Cov (X,Y) = `(Sigma (x_i - bar x) (y_i - bary))/n`
= `8000/100`
Cov (X,Y) = 80
Product moment correlation coefficient.
r = `(cov(X,Y))/(sigmax sigmay)`
= `80/(10 xx 12)`
r = 0.667
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