假设模型为Y t =α+βX t +μ t 。给定n个观察值(X 1 ,Y 1 ),(X 2 ,Y 2 ),…,X n ,Y n ,按如下步骤建立β的一个估计量:在散点图上把第1个点和第2个点连接起来并计算该直线的斜率;同理继续,最终将第1个点和最后一个点连接起来并计算该条线的斜率;最后对这些斜率取平均值,称之为 ,即β的估计值。 判定该估计值与我们以前用OLS方法所获得的估计值相比的优劣,并做具体解释。
【简答题】阅读下面短文 , 在空白处填入 1 个适当的单词或括号内单词的正确形式。 If you go out to the fields at night in spring or summer, you can hear frogs singing __ 1 __ (joy) here and there.It seems as if they were performing a field symph...
【简答题】Pay attention to the italicized parts in the English sentences and translate the Chinese sentences by simulating the structure of the English sentences. Is it not a joy to have friends come from afar?...
【简答题】听力 1. When are they going to leave? A. At 3:15 B. At 4:15 C. At 2:45 2. Who is Joy Bush? A. A computer maker. B. A book seller C. A writer 3. What does the woman say about Susan? A. She hasn't gone ca...