On the following graph, use the green point (triangle symbol) to plot the weekly total revenue when the market price is $20, $30, $40, $50, $60, $70, and $80 per scooter.

Total Revenue01020304050607080901001101201301030960890820750680610540470400TOTAL REVENUE (Dollars)PRICE (Dollars per scooter)

According to the midpoint method, the price elasticity of demand between points A and B is approximately .

Suppose the price of scooters is currently $30 per scooter, shown as point A on the initial graph. Because the demand between points A and B is , a $10-per-scooter decrease in price will lead to in total revenue per week.

In general, in order for a price decrease to cause a decrease in total revenue, demand must be .