The demand for books is: qd = 120 - p the supply of books is: qs = 5p 4) refer to scenario 2.1. what is the equilibrium price of books? a.5 b.15 c.20 d.10 e. none of the above

List x1, x2, x3, x4 where xi is the left endpoint of the four equal intervals used to estimate the area under the curve of f(x) between x = 4 and x = 6. a 4, 4.5, 5, 5.5 b 4.5, 5, 5.5, 6 c 4.25, 4.75, 5.25, 5.75 d 4, 4.2, 5.4, 6