An auditor for a county government would like to develop a model to predict county taxes, based on the age of single-family houses. She selects a random sample of 19 single-family houses, and the results are stored in Taxes.

1. Construct a scatter plot of age and county taxes.

2. Fit a quadratic regression model and state the quadratic regression equation.

3. Predict the county taxes for a house that is 20 years old.

4. Perform a residual analysis on the results and determine whether the regression model is valid.

5. At the 0.05 level of significance, is there a significant overall relationship between age and county taxes?

6. What is the p-value in (e)? Interpret its meaning.

7. At the 0.05 level of significance, determine whether the quadratic model is superior to the linear model.

8. What is the p-value in (g)? Interpret its meaning.

9. Interpret the meaning of the coefficient of multiple determination.

10. Calculate the adjusted r2.