I need some help please the decimal places part is hard even though it says round to 2 decimal places and I don't know if I got the round to the nearest whole dollar right

75p The cost to remove a toxin from a lake is modeled by the function C(p) = where C is the cost 85 - P (in thousands of dollars) and p is the amount of toxin in a small lake (measured in parts per billion [ppb]). This model is valid only when the amount of toxin is less than 85 ppb. a. Find the cost in dollars to remove 35 ppb of the toxin from the lake. C = $ 4772 (round to the nearest whole dollar) b. Find the formula for the inverse function. 850 P = f '(C) = 75 + C c. Use part b. to determine how much toxin is removed for $50,000. P = 35.41 * ppb (round to 2 decimal places)