Chapter 10, Problem 17E

(a)

To determine

To conduct: scatterplot of the mention data and tell about the straight.

Explanation of Solution

Given:

  

Graph:

  

The scattering plot shows a moderate to heavy, positive and slightly curved relation. Even if it is the relationship seems to be straight enough to try to match a linear model. The highest salary grew as the year went by.

(b)

To determine

To find: the regression equation between salary vs. year and draw the residuals.

Explanation of Solution

Given:

  

Graph:

  

Residual Plot:

  

By seeing the residual plot, it seems that the plot is showing the curvature nature, so linear model would not fit it well.

(c)

To determine

To Explain: the re-express the data and relation of the straighten if required.

Explanation of Solution

Given:

  

Graph:

Scatter Plot:

  

Residual Plot:

  

From the above result the regression equation is $\log \left(salary\right)=-109.133+0.055Year$ . R-squared of the model is 0.972 it implies that 97.2 percent of the variability in log of salary is accounted for by the model.

(d)

To determine

To find: the model report for the trend of the salaries.

Explanation of Solution

  $\log \left(salary\right)=-109.133+0.055Year$ this model is good for the trend in salary. Residual plot o this model represents no pattern therefore the linear model fits well.