Consider the Following to Answer the Question(s) Below

Multiple Choice

Consider the following to answer the question(s) below:
A company's manufacturing process uses 500 litres of water at a time. A "scrubbing" machine then removes most of a chemical pollutant before pumping the water into a nearby lake. To meet federal regulations the treated water must not contain more than 80 parts per million (ppm) of the chemical. Because there is a fine charged if regulations are not met, the company sets the machine to attain an average of 75 ppm in the treated water. The machine's output can be described by a Normal model with a standard deviation 4.2 ppm.
-What percent of the batches of water discharged exceed the 80 ppm standard?

A) 88.3%
B) 11.7%
C) 61.7%
D) 38.3%
E) -11.7%