2.20•4=8.80 so if you subtract that by 24.40 you get 15.60 and if you divide that by 4 you get 3.90 for each pendant. If you wanna check it you can add 3.90 and 2.20 together and multiply it by 4 and you get 24.40
The independent variable is the m, which is the number of minutes the hose has been running. The dependent variable is the g, which is the gallons per minute.