E.g 16.1 Annual Bonus and Years of Experience
Just calculate the Covariance and the variance of x.
We can use to estimate how well it is. And the deviations between the actual data points are called residuals
The residuals are observations of the error variable. The minimized sum of squared deviations is called the sum of squares for error ,which is called SSE.
Always remember, the interpretation of the coefficients pertains only to the sample. To infer information about the population, we need statistical inference techniques, which are described subsequently.
感悟练习题： 16.1-16.17 的习题的考点并不难 主要就考察协方差和方差的运算，会公式就行 会画图就行