Posted by Al on .
In cost in millions of dollars to remove x% of pollution is a lake modeled by C=5,000 over 2002x.
(a) What is the cost to remove 50% of the pullutant.

Algebra 
Reiny,
replace x with 0.5 in the formula and solve for C
C = 5000/(2002(.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%)