A tennis table is 120 cm by 60 cm while a ping pong table is 5 feet (150 cm) by 9 feet (270 cm). To check if the sizes are proportional, the lengths and widths of each table were divided by common factors. This resulted in different ratios for the lengths (40:3) and widths (12:1), showing the tennis and ping pong table sizes are not proportional to each other.