Problem
In a year, Tony rents 50 DVDs at $3 each and pays $50 for 10,000 gallons of tap water. Tony is maximizing total utility. If Tony's marginal utility from water is 0.5 unit per gallon, what is his marginal utility from a DVD rental?
The response should include a reference list. Double-space, using Times New Roman 12 pnt font, one-inch margins, and APA style of writing and citations.