posted by Al .
In cost in millions of dollars to remove x% of pollution is a lake modeled by C=5,000 over 200-2x.
(a) What is the cost to remove 50% of the pullutant.
replace x with 0.5 in the formula and solve for C
C = 5000/(200-2(.5))
take over ....
(something fishy here, the cost increased from 25 Million for doing nothing at all, to only 25.13 Million to remove 50%)