This document compares the sizes of tennis and ping pong courts. A tennis court is 78 feet long and 27 feet wide, while a ping pong table is 9 feet long and 5 feet wide. To determine if the sizes are proportional, the document calculates the width-to-length ratios for each court. The ratio for a tennis court is 27/78 = 5.4, while the ratio for a ping pong table is 5/9 = 8. Since these ratios are different numbers, the sizes of tennis and ping pong courts are not proportional to each other.