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Question
For a bivariate data: `bar x = 53, bar y = 28,` bYX = - 1.5 and bXY = - 0.2. Estimate Y when X = 50.
Solution
Given, `bar x = 53, bar y = 28,` bYX = - 1.5 and bXY = - 0.2.
`"a" = bar y - "b"_"YX" bar x`
∴ a = 28 - (- 1.5)(53) = 28 + 79.5 = 107.5
Now, the regression equation Y on X is
Y = a + bYX X
i.e., Y = 107.5 + (- 1.5)X
i.e., Y = 107.5 - 1.5 X
When X = 50, we get
Y = 107.5 - 1.5 × 50 = 107.5 - 75 = 32.5
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