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小王爱学习 · 2022年01月18日

我求出来也是 a=-1.921273 b=2.508061

NO.PZ2020010801000009

问题如下:

Find the OLS estimators for the following data:

选项:

解释:

Doing the basic needed calculations:

β^=(XiX)(YiY)(XiX)2=20.83/8.25=2.52\widehat\beta = \frac{\sum (X_i-\overline X)(Y_i-\overline Y)}{\sum (X_i-\overline X)^2}=20.83/8.25=2.52

α^=Yβ^X=9.42.524.5=1.96\widehat\alpha = \overline Y-\widehat\beta \overline X=9.4-2.52*4.5=-1.96

Continuing to estimate the variance:

s2=1n2iϵ^i2=110244.41=5.55s^2=\frac{1}{n-2}\sum_{i} \widehat\epsilon_i ^2=\frac{1}{10-2}44.41=5.55

我用计算器按出来结果是 a=-1.921273 b=2.508061,和前面同学一样,是哪里出了问题???

1 个答案

李坏_品职助教 · 2022年01月18日

嗨,从没放弃的小努力你好:


是的同学,你算的是对的,这道题确实有点问题,我来反馈一下。

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努力的时光都是限量版,加油!

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