6. Refer to Problem 9.24. For those counties, Table 9.9 shows part of the printout for the regression analysis relating Y = median income (thousand of dollars) to X = percent of residents with at least a high school education.

a) Report the prediction equation, and interpret the slope

b) Is the y-intercept meaningful" Explain

c) Find the predicted median income for a county with 70% of the residents having at least a high school education.

d) County A has 10% more of its residents than county B with at least a high school ed- ucation Find their difference in predicted median incomes.

e) Find the Pearson correlation Interpret using (i) the sign (ii) the magnitude, (iii) the standardized slope.

f) Find the coefficient of determination Explain its PRE interpretation. TABLE 9.9 Variable Mean Std Dev Parameter --- Variable Estimate INCOME EDUCATIO 24.51 4.69 69.49 8.86 INTERCEP -4.63 EDUCATIO 0.42