Answer:
Independent variable: Number of tickets sold
Dependent variable: Number of t-shirts earned
Step-by-step explanation:
Possibilities:
The amount of t-shirts earned depends on the number of tickets sold
or
The number of tickets sold depends on the number of t-shirts earned
Possibility #1 makes the most since, because the number of tickets sold is the controlled value. The independent variable can always be controlled
Independent variable: Number of tickets sold
Dependent variable: Number of t-shirts earned
Hope this helps :)