NO.PZ202208220100000104
问题如下:
Identify which chart, among Charts 2, 3, and 4, is most likely to be used to assess homoskedasticity.
选项:
A.Chart 2 B.Chart 3
解释:
C is correct. To assess homoskedasticity, we must evaluate whether the varianceof the regression residuals is constant for all observations. Chart 4 is a scatterplot of the regression residuals versus the predicted values, so it is very usefulfor visually assessing the consistency of the variance of the residuals across the observations. Any clusters of high and/or low values of the residuals may indicatea violation of the homoskedasticity assumption.
这个图怎么看出同方差?是因为图4是残差图可以看出吗?为什么图2、3都不能看出呢?X和Y的图应该也可以看出。我咋觉得图2、3、4都差不多