(a) Centering the data (9 points) Well, that plot looks nice. But notice the scale of the axes. The x-axis has a range of about [10,90] and the y-axis has a range of [20,000,90,000] . These ranges raise two issues with respect to the interpretation of a regression model: Recall that the intercept parameter is interpreted as the mean of the response when each predictor is zero. But in this case, zero is not a meaningful value for the age predictor. Recall that a slope parameter in multiple linear regression is interpreted as the average change in the response for a one-unit increase in the value of the corresponding predictor, holding other predictors constant. But, for this problem, do we really care about how a "one dollar increase in (yearly) salary" impacts turtle rating? Probably not. It would be more convenient to interpret the change turtle rating with respect to bigger jumps in income, say, one thousand dollar increases