问题如下：
Based on Exhibit 2, Vasileva should compute the:
选项：
A.coefficient of determination to be 0.4689.
95% confidence interval for the intercept to be –0.0037 to 0.0227.
95% confidence interval for the slope coefficient to be 0.0810 to 0.3898.
解释：
C is correct. The confidence interval for the slope coefficient is calculated as:
Confidence interval = b1 ± t c * sb1
Where b1 = 0.2354, sb1 = 0.0760 and tc = 2.032
The lower limit for the confidence interval = 0.2354 – (2.032 × 0.0760) = 0.0810
The upper limit for the confidence interval = 0.2354 + (2.032 × 0.0760) = 0.3898
t分布常用的单双尾的交界值能分别告知下吗？很混乱。比如阿尔法=0.05时的单双尾检验值分别是1.645和2.032对吗？？？那么=0.1或0.01时呢？
