Answer:
Dependent Variable = tips left by male customers
Independent Variable = T-Shirt color worn by waitresses
Explanation:
Dependent variable is the variable that changes when the independent variable changes.
In other words, when the independent variable is varied, the dependent variable changes. The dependent variable is the effect or outcome of the manipulation of the independent variable.
In the study referred to in the question above, the amount of tips given to waitresses is dependent on the color of the T-shirt the waitresses wear.
Therefore, the dependent variable is T-Shirt color, while the independent variable is the amount of tips given.