題組內容

5. (15%)An OLS regression has the following data: \( \bar{X} = 3 \); \( \bar{Y} = 4 \); \( \sum(X - \bar{X})^2 = 32 \); \( \sum(Y - \bar{Y})^2 = 29 \); \( \sum(X - \bar{X})(Y - \bar{Y}) = 28 \); The sample observation size is 10. Please calculate:

(2)(5%)The variance of residuals \( \hat{\sigma}^2 \)。