Chapter 10, Problem 26E

(a)

To determine

To construct: the again modal by eliminating that data point which considered competitor to be an outlier.

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:

Data analysis

Data > Data analysis > Regression

Step 1. Enter data in excel spreadsheet

Step 2. Click on Data > Data analysis > Regression.

Step 3. Select input Y and X range

Step 4. Click Ok

This is the obtained output

  

Therefore, from the output, the regression line is

  $weightlifted=164.97+2.56weightclass$

(b)

To determine

To find: how much the outlier competitor would have predicted to raise, using this updated model.

Answer to Problem 26E

308.33 kg

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:

According to the revised model, it is expected the weight lifted by the competitor who is having the considered as the outlier, if know his weight class. The weight class of the is 56 kg. therefore, the predicted by this is given by this regression model of the part (a) is

  $\begin{array}{c}weightlifted=164.97+2.56weightclass\\ =164.97+2.56\left(56\right)\\ =164.97+143.36\\ =308.33\end{array}$

Therefore, it would predicted the competitor to lift is 308.33 kg.

(c)

To determine

To Explain: the meaning of residual from the new updated model for that competitor.

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:

Difference between the expected value and the actual value is residual

Therefore, the residual of the competitor is

308.33-295=13.33 kg

It means that the competitor would be expected to lift an extra weight of 13.33 kg to get 295 kg which he actually lifted.