问题如下:
6.Based on Exhibit 2, the degrees of freedom for the t-test of the slope coefficient in this regression are:
选项:
A.48.
B.49.
C.50.
解释:
A is correct.
The degrees of freedom are the number of observations minus the number of parameters estimated, which equals two in this case (the intercept and the slope coefficient). The number of degrees of freedom is 50− 2 = 48.
之前的解答写道:回归的t检验的自由度df=n-k-1,其中k为自变量的个数,1为常数项。本题k=1,所以自由度为50-2=48.
ANOVA表里残差的自由度也是n-k-1。所以都是n-k-1,对吧?二者有啥区别吗?