Answer:
c the price elasticity of demand is about 1.43 and an increase in the airfare will cause airlines' total revenue to decrease.
Step-by-step explanation:
q1 2,000 p1 250
revenue1 = quantity x price = 2,000x250 = 500,000
q2 1,700 p2 280
revenue2 = 1,700 x 280 = 476,000
Midpoint formula:
![E_p(q_1-q_2)/((q_1+q_2)/(2)) /(p_1-p_2)/((p_1+p_2)/(2))](https://img.qammunity.org/2020/formulas/business/college/6j7ayjalvpv33biac13d67gt2uktizw1rq.png)
![(2,000-1,700)/((2,000+1,700)/(2)) /(250 - 280)/((250 + 280)/(2))](https://img.qammunity.org/2020/formulas/business/college/a6o5fgak5igytom1dwcx92rft5rcie0tbo.png)
![(300)/(1850) /(-30)/(265)](https://img.qammunity.org/2020/formulas/business/college/hkipshsh73je4i5cubtfn3bbfl4dlj0uia.png)
Ep = -1.432432432
As the price elasticity is above -1 the decrease in quantity is greater than the decrease in price thus, the revenue of the firm decreases if increase the price.