Given:
The local rate for electrical service is 6 cents per kilowatt-hour.
We need to know how much money would be saved in a year by using a dishwasher 4times per week rather than 6 times per week
From the table:
The cost of using a dishwasher 4 times per week = $29
The cost of using a dishwasher 6 times per week = $44
So, the saving will be = 44 - 29 = 15
So, the answer will be $15