Chapter 10, Problem 24E

(a)

To determine

To construct: the linear model for the weight lifted in every weight class.

Explanation of Solution

Given:

Weight class	Weight Lifted
56	295
62	325
69	347.5
77	375
85	382.5
94	407.5
105	425

Calculation:

Creating the model below is the output the given input

  

Graph:

  

From the above output the regression line would be

  $weightlifted=164.97+2.56weightclass$ R-squared model is 0.963 which implies that 94.3 percent of the variability in weight lifted is estimated for by the model.

(b)

To determine

To check: residual plot and tell about the linear model is appropriate or not.

Explanation of Solution

Graph:

Residual output of the model is

  

By seeing the residual output, it seems that it is curvature in the nature, therefore linear mode would not be fit in the model.

(c)

To determine

To construct: the better model.

Explanation of Solution

Given:

Weight class	Weight Lifted
56	295
62	325
69	347.5
77	375
85	382.5
94	407.5
105	425

Calculation:

Re-expressing the data using the reciprocal of the class

Weight class	Weight Lifted	1/weight class
56	295	0.017857143
62	325	0.016129032
69	347.5	0.014492754
77	375	0.012987013
85	382.5	0.011764706
94	407.5	0.010638298
105	425	0.00952381

Graph:

  

By seeing the scatter plot it seem that equation line looks similar, negative and strong.

(d)

To determine

To Explain: the reason for the better of new model.

Explanation of Solution

Given:

Re-expressing the data using the reciprocal of the class

Weight class	Weight Lifted	1/weight class
56	295	0.017857143
62	325	0.016129032
69	347.5	0.014492754
77	375	0.012987013
85	382.5	0.011764706
94	407.5	0.010638298
105	425	0.00952381

Graph:

  

  

A better model than the original prototype is the reciprocal model. This model's plot of residualsThen the prior residual plot shows no pattern. And the model accounts for 99.4% of theWeight lift variability, which is considerably higher than the previous iteration.

(e)

To determine

To explain:the which of the medallists turned in the most surprising performance.

Answer to Problem 24E

Georgia

Explanation of Solution

By seeing the residual plot it is much clear that Georgia is having the highest negative residual which is most lifted lesser weight than expected by him.