NO.PZ2020010801000009
问题如下：
Find the OLS estimators for the following data:
选项：
解释：
Doing the basic needed calculations:
老师在强化班的课程里提到OLS ESTINATORS这块时好像说主要掌握性质，所以像本题这样的计算是否有很大必要花时间去掌握呢？
NO.PZ2020010801000009问题如下Finthe OLS estimators for the following t ing the basic neecalculations: β^=∑(Xi−X‾)(Yi−Y‾)∑(Xi−X‾)2=20.69/8.25=2.508\wihat\beta = \frac{\sum (X_i-\overline X)(Y_i-\overline Y)}{\sum (X_i-\overline X)^2}=20.69/8.25=2.508β=∑(Xi−X)2∑(Xi−X)(Yi−Y)=20.69/8.25=2.508α^=Y‾−β^X‾=9.365−2.508∗4.5=−1.921\wihat\alpha = \overline Y-\wihat\beta \overline X=9.365-2.508*4.5=-1.921α=Y−βX=9.365−2.508∗4.5=−1.921 想问一下 考试会出需要算这么多的题吗
NO.PZ2020010801000009问题如下Finthe OLS estimators for the following t ing the basic neecalculations: β^=∑(Xi−X‾)(Yi−Y‾)∑(Xi−X‾)2=20.69/8.25=2.508\wihat\beta = \frac{\sum (X_i-\overline X)(Y_i-\overline Y)}{\sum (X_i-\overline X)^2}=20.69/8.25=2.508β=∑(Xi−X)2∑(Xi−X)(Yi−Y)=20.69/8.25=2.508α^=Y‾−β^X‾=9.365−2.508∗4.5=−1.921\wihat\alpha = \overline Y-\wihat\beta \overline X=9.365-2.508*4.5=-1.921α=Y−βX=9.365−2.508∗4.5=−1.921 有x和y两组数据，请问为什么不能通过直接按计算器得到a和b呢？
NO.PZ2020010801000009问题如下Finthe OLS estimators for the following t ing the basic neecalculations: β^=∑(Xi−X‾)(Yi−Y‾)∑(Xi−X‾)2=20.69/8.25=2.508\wihat\beta = \frac{\sum (X_i-\overline X)(Y_i-\overline Y)}{\sum (X_i-\overline X)^2}=20.69/8.25=2.508β=∑(Xi−X)2∑(Xi−X)(Yi−Y)=20.69/8.25=2.508α^=Y‾−β^X‾=9.365−2.508∗4.5=−1.921\wihat\alpha = \overline Y-\wihat\beta \overline X=9.365-2.508*4.5=-1.921α=Y−βX=9.365−2.508∗4.5=−1.921 是不是上下各除以了一个n然后抵消了？
NO.PZ2020010801000009 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？？？
