# Question

Suppose r2 = 0.30. Since ∑ (y - )2 is used in estimating the overall variability of the y values and ∑ (y - )2 is used in estimating the residual variability at any fixed value of x , explain why approximately the estimated variance of the conditional distribution of y for a given x is 30% smaller than the estimated variance of the marginal distribution of y.

## Answer to relevant Questions

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