An environmental engineer is supervising a remediation effort concerning a particular body of
water. When she arrives on site, the engineer determines that the pollution is 530 ppm. Six
hours later, she takes another measure of the pollution and finds the pollution level is 400 ppm.
a. Construct a linear model relating the level of pollution in ppm to the time spent on
radiation in hours. (label your variables)
b. Predict what the level of pollution would be 9 hours after the remediation efforts began.