Julio will live and work forever, he borrows and lends at a 4 percent annual interest rate, and he has no out-of-pocket expense of attending school. The table below list Julio's weekly wage for each completed grade of school.

SHOOLING (grade)	WAGE ($/week)	WAGE CHANGE ($/week/grade)	MARGINAL RATE OF RETURN (%/grade)
8	1,059
9	1,175
10	1,293
11	1,409
12	1,522
13	1,628
14	1,726
15	1,812
16	1,885
17	1,941
18	1,980
19	2,000
20	2,000

1. For each grade, use the conventional method to compute Julio's marginal rate of return to schooling D_w/_w.

1. Julio's marginal rate of return to schooling fall to 2 percent at grade ______

1. To maximize wealth, Julio quits school after completing which grade?

1. If Julio chooses schooling sto maximize his marginal rate of return to schooling, he completes ________ grades.

1. Lea and Julio have the same wage-schooling curve, but Lea faces an 8 percent annual interest rate. At what grade does wealth-maximizer Lea finish her education?