11.7. Table 9.16 on page 297 showed data from Florida counties on y = crime rate (number per 1000 residents), X| = median income (thousands of dollars), and X2 = percent in urban environment.

(a) Figure 11.12 shows a scattcrplot relating y to xj. Predict the sign that the estimated effect of x\ has in the prediction equation y = a +

/?xi