#### Answer

Estimate: 80,000,000; Exact: 76,529,550

#### Work Step by Step

To estimate, we round 209,670 gallons to 200,000 and 365 days to 400. We find the estimated number of gallons of water polluted per year by multiplying 200,000 * 400 = 80,000,000. We find the exact number of gallons of water polluted per year by multiplying 209,670 * 365 = 76,529,550