Problem - Length, width, and weight of perch. Here are data for 12 perch caught in a lake in Finland:
|
Weight (grams)
|
Length (cm)
|
Width (cm)
|
|
Weight (grams)
|
Length (cm)
|
Width (cm)
|
|
5.9
|
8.8
|
1.4
|
|
300.0
|
28.7
|
5.1
|
|
100.0
|
19.2
|
3.3
|
|
300.0
|
30.1
|
4.6
|
|
110.0
|
22.5
|
3.6
|
|
685.0
|
39.0
|
6.9
|
|
120.0
|
23.5
|
3.5
|
|
650.0
|
41.4
|
6.0
|
|
150.0
|
24.0
|
3.6
|
|
820.0
|
42.5
|
6.6
|
|
145.0
|
25.5
|
3.8
|
|
1000.0
|
46.6
|
7.6
|
In this exercise we will examine different models for predicting weight.
(a) Run the regression using length to predict weight. Do the same using width as the explanatory variable. Summarize the results. Be sure to include the value of r2.
(b) Plot weight versus length and weight versus width. Include the least-squares lines in these plots. Do these relationships appear to be linear? Explain your answer.