Using regression analysis on data from a field experiment, the demand curve for a product is estimated to be $,$ Qzd$=1,200-3$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?$

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