a) Y=0.12x and the Y value is dependent whole X value is independent
b) Just make a table and multiple each value by the equation
c) The domain would be the lowest and highest values of X and the range would be the lowest and highest values of Y (double check me on this to be sure)
d) A day = (0.12)(300)+(0.12)(750)+(0.12)(1050)
A week = (0.12)(300)+(0.12)(750)+(0.12)(1050) and multiply that by 7