Nicole and Amy share an apartment and work at Pure H2O Engineering, and they have decided to drink more water each day. The recommended amount is eight 8-ounce glasses, or 64 ounces, per day. This is a total of one gallon per day for the two of them. Using this 1 gallon (or 3.78 liters equivalent) basis for three possible sources of drinking water, determine the monthly cost and present worth value for one year of use. For each source, the average cost and amount of source water estimated to be used to get a gallon of drinking water is tabulated. Let i 6% per year com- pounded monthly and assume 30 days per month.