Using the listed old / new mpg ratings, find the best predicted new mpg rating for a car with an old rating of 30 mpg. Is there anything to suggest that the prediction is likely to be quite good?

In each case, find the regression equation, letting the first variable be the predictor (x) variable. Find the indicated predicted value by following the prediction procedure summarized in Figure 10-5 on page 493.
Figure 10-5

Old 16 27 17 33 2824 18 22 20 2921 New 15 24 15 29 2522 16 20 1826 19 Strategy for Predicting Values of y Is the regression equation a good model? The regression line graphed in the scatterplot shows that the line fits the points well. r indicates that there is a linear correlation. The prediction is not much beyond the scope of the available sample data. Yes. The regression No. The regression equation is not a good model. equation is a good model. Substitute the given v into the regression equation alue of X Regardless of the value of x, the best predicted value of y is the value of y (the mean of the y values)