The marginal revenue function on sales of q units of a product is R' (q) = 240-18√q dollars per unit.

Estimate the total revenue if sales are 100 units.

What is the marginal revenue at 100 units?

Estimate the total revenue if sales are 101 units.

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Total revenue R (q) = ∫R' (q) dq = ∫ (240 - 18√q) dq = 240q - 12q^3/2

R (100) = 240 (100) - 12 (100) ^3/2 = 24000 - 12 (1000) = $12,000

Marginal revenue at 100 units R' (100) = 240 - 18√100 = 240 - 18 (10) = $60

Revenue at 101 units = R (101) = 240 (101) - 12 (101) ^3/2 = 24,240 - 12,180 = $12,060