Question

A US consumer lobby wishes to develop a model to predict gasoline usage, as measured by miles per gallon, based on the weight of the car in pounds. The Excel data file AUTO.xls (contained in a folder under the CML Quizzes tab) contains data on this for fifty recent models. Use Excel Data Analysis to estimate a linear model for the relationship, a 95% confidence interval for the slope coefficient and the residual plot. State all numeric answers below correct to four decimal places using the Excel output results.
1. the intercept  
2. the slope coefficient , and
3. the coefficient of determination  
4. Using this model, predict the gasoline usage for a car weighing 3000 pounds. Use all decimal places in your calculation by selecting and using the values of b₀ and b₁ in the output generated by Excel.
5. Does the prediction involve extrapolating the relationship? Type yes or no.
State the
6. lower bound  
7. upper bound  for the 95% confidence interval for the slope coefficient

Answer 1