A residual plot with histogram and normal probability plot of the
residuals are added to the analysis task pane.
An influence plot is added to the analysis task pane.
The residual plot and normality plot show that the assumptions do not seem to be
(click to enlarge)
the influence plot shows that McDonald's has a large influence on the fit.
Looking again at the scatter
plot and fit shows there is a downturn in the fitted line, compared to the data, as the
spend increases. It might be worth considering alternative models to better describe the