Answer: -0.043
Explanation:
You didn't really say what you really want to solve but looking at this, I believe it should be the price elasticity of demand.
The formula for calculating the price elasticity of demand will be:
= Percentage change in quantity demanded / Percentage change in price
Percentage change in quantity demanded = (90 - 100) / 100 × 100
= -10/100 × 100
= -10
Percentage change in price = (1000 - 300) / 300 × 100
= 700/300 × 100
= 233
Price elasticity of demand = -10/233 = -0.043
