Answer:
$14
Step-by-step explanation:
The revenue from sales of fans is the product of the number of fans sold and the price at which they are sold:
R(p) = n·p = (1960-70p)p
R(p) = 70(28 -p)p
This equation describes a parabola that opens downward and has zeros at p=0 and p=28. The axis of symmetry is halfway between those zeros, at p=14. It goes through the vertex or point of maximum revenue.
The price for maximum revenue is p = 14 dollars.
