Using regression analysis on data from a field experiment, the demand curve for a product is estimated to be Qzd$=1200-3$pz$-\mathrm{.}1$pz $,$ where Pz $=$ $$300.($LO$1,$ LO$4,$ LO$5)$ What is the own price elasticity of demand when Px $=$ $$140?$ Is demand elastic or inelastic at this price? What would happen to the firm$$s revenue if it decided to charge a price below $$140?$ What is the own price elasticity of demand when Px $=$ $$240?$ Is demand elastic or inelastic at this price? What would happen to the firm$$s revenue if it decided to charge a price above $$240?$ What is the cross$-$price elasticity of demand between good X and good Z when Px $=$ $$140?$ Are goods X and Z substitutes or complements?

Baye, Michael. Managerial Economics & Business Strategy $($p$.287).$ McGraw$-$Hill Higher Education. Kindle Edition.