Table 9.15 in Exercise 9.39 shows countywide data for several variables in Florida. For those counties, Table 9.10 shows part of the output for the regression analysis relating y = median income (in thousands of dollars)

to x = percentage of residents with at least a high school education.

(a) Report the prediction equation, and interpret the slope.

(b) CountyAhas 10% more of its residents than county B with at least a high school education. Find their difference in predicted median incomes.

(c) Find the correlation. Interpret using (i) the sign,

(ii) the magnitude, (iii) the standardized slope.

(d) Find r2. Explain how to interpret it.