Practice Problems # 12
1. The following table gives values for hypothetical variables x and y.
x y x y
1.0 2.2 11.0 31.5
2.0 9.0 12.0 32.7
3.0 13.5 13.0 34.9
4.0 17.0 14.0 36.3
5.0 20.5 15.0 37.7
6.0 23.3 16.0 38.7
7.0 25.2 17.0 40.0
8.0 26.4 18.0 41.3
9.0 27.6 19.0 42.5
10.0 30.2 20.0 43.7
a. Create a scatter plot of y versus x.
b. Fit a simple linear regression model to this data.
c. Using the model in part b, create a residual plot of the residuals vs. x.
d. Create a residual plot of the residuals vs. fitted values.
e. Do these plots indicate an adequate fit? Explain.
f. Fit a second degree first order linear regression model to this data.
g. Does it seem adequate? Provide the ANOVA table and F test.