问题如下:
7. The upper bound for the 95% confidence interval for the coefficient on the debt ratio in the regression is closest to:
选项:
A. −1.0199.
B. −0.3947.
C. 1.4528.
解释:
B is correct.
The calculation for the confidence interval is −4.1589 ± (2.011 ×1.8718). The upper bound is −0.3947. The 2.011 is the critical t-value for the 5% level of significance (2.5% in one tail) for 48 degrees of freedom.
为啥不能用1.96?