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Lecture 3: Multiple Regression Model - McCombs School of Business

Lecture 3: Multiple Regression Model - McCombs School of Business

Lecture 3: Multiple Regression Model - McCombs School of Business

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Garbage Data<br />

◮ R 2 is 26% !!<br />

◮ As usual, we need a statistical notion <strong>of</strong> how close is close...<br />

◮ It turns out that if we transform R 2 we can solve this.<br />

Define<br />

f =<br />

R 2 /(p − 1)<br />

(1 − R 2 )/(n − p)<br />

This is the F-test <strong>of</strong> overall significance. Under the null hypothesis<br />

f is distributed:<br />

f ∼ F p−1,n−p<br />

24

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