Euclid's Muse

This is an example of the Trapezoidal Sum Rule. Here we have the rough average rates of the water exiting the Columbia River at Bonneville Dam on the Oregon and Washington border between 1938 and 1998, where at x=0 is 1938 and every 5 years is marked by 10000x. So at x=120000, the year is 1998. The formula to find the integral of the data, or the sum of the amount of water that flowed out of Bonn…