Answer :

AL2006
The amount of money I spend putting gas in my car this week is

      B  = 3.079 G

where
' B '  is the number of Bux I spend on gas this week.
' G '  is the number of Gallons I buy this week.

-- The independent variable is 'G'.  I can buy as few or as many gallons
as I want to.

-- The dependent variable is ' B '.  It depends on how many gallons I buy.