5. Two hundred years ago, as it became more and more evident that this country would sever all ties with England, a large number of people who had moved here decided to return to their former home. This migration was so large, in fact, that by July 4, 1776, it had decreased the American population by 20%, and increased the population of the British Isles by 4%. Assuming that no one who left America went anywhere else, what percent of the British population was the American population before the migration? 7. A factory along the Mississippi River draws in river water that contains 10% more pollutants than \"clean\" water (even clean water contains some pollutants). The water is used in a manufacturing process that causes the water to leave the plant containing 23% more pollutants than the water taken in. A municipal treatment facility downstream draws water in and removes 75% of all pollutants. How dirty is the water after going through the munici- pal treatment facility as compared to \"clean\" water