问题如下：
Batten runs a regression analysis using Stellar monthly returns as the dependent variable and the monthly change in CPIENG (US Consumer Price Index for Energy) as the independent variable. All of the data are in decimal form, where 0.01 indicates a 1 percent return.
Based on the regression, which used data in decimal form, if the CPIENG decreases by 1.0 percent, what is the expected return on Stellar common stock during the next period?
选项：
A. 0.0073 (0.73 percent).
B. 0.0138 (1.38 percent).
C. 0.0203 (2.03 percent).
解释：
C is correct.
From the regression equation, Expected return = 0.0138 + -0.6486(-0.01) = 0.0138 + 0.006486 = 0.0203, or 2.03 percent.
请问为什么bo直接使用表格给定的，而不像b1一样用公式把标准差带入计算一遍呢？
