Answer:
4) -0.5.
Explanation:
The mid point formula for determining the price elasticity coefficient can be calculated using the following formula:
Price elasticity co-efficient=((D2-D1)/(D2+D1/2))/((P2-P1)/(P2+P1/2))
In this question:
D2=19,000, D1=21,000, P2=$0.55, P1=$0.45
Price elasticity co-efficient=((19,000-21,000)/(19,000+21,000/2))/((0.55-0.45)/(0.55+0.45/2))
Price elasticity co-efficient= Â -0.50
So based on the above calculation, the answer is 4) -0.5.