For Exercises 2.44 and 2.45, see page 82; for 2.46, see page 84; for 2.47, see page 86; for 2.48 and 2.49, see page 88; for 2.50, see page 90; for 2.51, see page 90; for 2.52, see page 91; and for 2.53, see page 94.
2.71 Add an outlier
Refer to the previous exercise. Add an additional case with and to the data set. Repeat the analysis that you performed in the previous exercise and summarize your results, paying particular attention to the effect of this outlier.
gendatb
2.71
(a) There seems to be a weak positive linear relationship between and , but with one extreme outlier with a very high value. (b) . (d) (e) Although the variable accounts for 77.15% of the variation in , there is a very high outlier for , which pulls the regression line unnaturally. This is seen in the jump of the -square value from 27% up to 77%, indicating that this observation is very influential in the analysis. This is also demonstrated by the systematic pattern in both the scatterplot and the residual plot, with most of the data points forming a line except for the outlier.