Suppose the demand curve is given by Q = 200 - 20P. Answer the following. (a) What is the price elasticity at P = $4? Is demand elastic or inelastic at this point? (b) What is the price elasticity at P = $7? Is demand elastic or inelastic at this point? (c) At what price is revenue maximized (where demand is unit elastic)? (d) Illustrate your answers with a labeled demand curve.