STAT3002 Week 3

 

1. Residuals

 

Hypothetical Data. The following data sets have been artificially designed.  Source: Weisberg, 1986.

 

X

Y

 

X

Y

 

X

Y

 

X

Y

10

8.04

 

10

9.14

 

10

7.46

 

8

6.58

8

6.95

 

8

8.14

 

8

6.77

 

8

5.76

13

7.58

 

13

8.74

 

13

12.74

 

8

7.71

9

8.81

 

9

8.77

 

9

7.11

 

8

8.84

11

8.33

 

11

9.26

 

11

7.81

 

8

8.47

14

9.96

 

14

8.1

 

14

8.84

 

8

7.04

6

7.24

 

6

6.13

 

6

6.08

 

8

5.25

4

4.26

 

4

3.1

 

4

5.39

 

19

12.5

12

10.84

 

12

9.13

 

12

8.15

 

8

5.56

7

4.82

 

7

7.26

 

7

6.42

 

8

7.91

5

5.68

 

5

4.74

 

5

5.73

 

8

6.89

 

> temp1 <- read.table("clipboard", header=T)

> plot(temp1$X,temp1$X)

> temp1.lm <- lm(temp1$Y ~ temp1$X)

> abline(temp1.lm)

 

Each data set leads to the same summary regression statistics, namely

yi = 3.0 + 0.5 xi + ei,       s2 = 13.75,    R2 = 0.667

 

> plot(fitted(temp1.lm),residuals(temp1.lm))

> qqnorm(residuals(temp1.lm))

> qqline(residuals(temp1.lm))