Chapter 27, Problem 25E

To determine

To explain which of the assumptions for inference are violated.

Explanation of Solution

Given:

  

  

The conditions are: straight enough, Independence, Randomization, Random residual, does plot thicken? and Nearly normal condition.

1) Plot of the Calories vs Fiber does not look linear.

2) The plot of Actual vs predicted residual should contain errors spread out randomly which are not observed in the residual plot. So, random residual assumption violated.

3) The histogram of residual is right-skewed; Hence, assumption of symmetry is violated.