math
posted by lindsey on .
Biologists want to set up a station to test alligators in the lake for West Nile Virus. Suppose that the costs for such a station are $3,000 for setup costs and $4.00 to administer each test.
a. Write an expression that gives the cost(C) to test animals.
b. you can find the average cost per animal by dividing total costs by number of animals. Write the equation that gives the average cost (AC) per animal.
c. Find the average cost for 20 animals.
d. Find the average cost for 200 animals.
e. Find the average cost for 2000 animals.
f. How many animals should be tested for the average cost to be $5.00 per animal?

a. C = 4X + 3000.
b. AC = (4X + 3000) / X.
c. AC = (4*20 + 3000) / 20 = $154.
d.
e.
f. AC = (4X + 3000) / X = $5.00,
Multiply both sides by x:
4X + 3000 = 5X,
5X  4X = 3000,
X = 3000 Animals.