Yes its proportional, I mean number of hours and earned dollars. ITs because if she stay at work 2 times more she will earn 2 times more.
Proportional is relation where is 1 is growing second is growing too.
In mathematical point of view proportionality is when there is no variable taken to the power of 2 or something else, and if there is no situation shown in example below
[tex]y= \frac{2}{x} [/tex] - its not proportional
Because if x is getting greater, RHS is going to be smaller, so y is going to be smaller when x is growing.
