The classic way to convey the error that exists in a measurement is a formula that shows the obtained measurement (X) as a sum of a true score plus some error. One version of this formula is: X = T + e. With this formula in mind, obtaining more precise measures depends on reducing error.
  Mega is the prefix meaning one million, therefore there are one million (1,000,000) gallons in a mega gallon.
Convert the answer to gallons. To convert the answer to gallons, simply multiply the answer by 7.48. 4,400 x 7.48 = 32, 912 gallons of water. You're all done.