Question: Prove that xy = x y x y ,where x and y are the means of {x i } and {y i },

Prove that σ_xy= x̅ y̅ – x̅ y̅ ,where x̅ and y̅ are the means of {x_i} and {y_i}, respectively, while x̅ y̅ denotes the mean of the product variable {x_iy_i}.

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