Iwould really appreciate some with this science question!

the typical shower releases water at a rate of five gallons per minute. for your family calculate the water savings per year (in dollars), if each person in your family reduces the time of showers by just one minute. explain your calculations.

i looked at it and came up with this formula, but i don't know what to do with

4 family members * 10min/day / person * 365 days / year * 5 gallons of water / minute = 73,000 gallons of water per year.