The Department of Transportation conducted a study to determine the relation between engine size and fuel consumption in compact cars. The engine size is given in liters (independent variable), and the mileage is given in miles per gallon (dependent variable). Data was collected for five types of cars. The equation of the regression line y = 38.66 - 4.99x and a standard error of the slope 1.22 represents the data collected from the study.
1. Find a 95% confidence interval for the slope.
2. If sd = 3.35, give a 95% confidence interval for the MPG of a car with a 3 liter engine.