More Ellipses

Each of the problems below is a link. If you click on the problem, it will take you to a YouTube video of a full, step-by-step solution for the problem. You may try these problems as practice and use the videos to check your answer, or you can just watch the videos to see more worked-out example problems.

Find the equation of the ellipse with foci left paren plus or minus 8 comma 0 right paren and eccentricity e = 4 fifths, and sketch its graph
Find the equation of the ellipse with foci left paren 0 comma plus or minus 3 right paren and eccentricity e = 3 fifths, and sketch its graph
Inside the U.S. Capitol Building in Washington D.C., there is an elliptical-shaped room called Statuary Hall. It is said that John Quincy Adams put his desk at one of the foci in the room so that he could hear other politicians whispering to each other near the other focus. If the room is 97 feet long along its major axis and 46 feet wide along its minor axis, find the distance between the foci, rounded to the nearest foot.