A chemistry teacher working at a golf camp during the summer found a liquid, which caused him to slice ball after ball into the water without disturbing him at all. He thought that this was an important liquid to identify so he set out to determine its density. He found that a sample of the liquid had a mass equal to 455 golf balls and occupied a volume of 620 water cups that he obtained at the 7 th hole. Each golf ball massed 50 g and the water cups at the 7 th hole of the golf course held 45 mL each. What is the density of the unknown liquid?