Statistics for Business: Decision Making and Analysis, 3rd Edition

... association to residuals.

If you look very closely back at Figure 19.6, you will discover that the plot on the right in the lower row matches the original plot of the residuals shown in Figure 19.6. The similarity of these four makes it difficult to distinguish the original residual plot. Hence, we would conclude that there is no clear pattern in the residual plot. The fitted regression line captures the pattern that relates weight to price.

Standard Deviation of the Residuals

A regression equation should capture the pattern and leave behind only simple random variation. If the residuals are “simple enough” to be treated as a sample from a population, we can summarize them in a histogram.

The histogram of the residuals in the example of diamonds appears ...