Question 158736
2.	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 $2,500 for setup costs and $3.00 to administer each test. 

a.	Write an expression that gives the total cost to test x animals.

3x+2500

b.	You can find the average cost per animal by dividing total costs by number of animals. Write the expression that gives the average cost per animal.

3x+2500 / x

c.	Find the average cost per animal for 10 animals. 100 animals. 1,000 animals.

3(10)+2500/10 = 30+2500/10= 2530/10=$253
3(100)+2500/100 = 300+2500/100 = 2800/10=$28
3(1000)+2500 / 1000 = 3000+2500 / 1000= 5500 / 1000 = $5.50

d.	As the number of animals tested increases, what happens to the average cost to test the animals? Would the average cost ever fall below $3.00? If so, identify a value that supports your answer. If not, explain how you know. 

no

e.	How many animals should be tested for the average cost to be $5.00 per animal? 

5=3x+2500/x
first multiply by the denominator on both sides.
5x=3x+2500
now solve.
2x=2500
x=1250