To transform the first graph, which represents a proportional relationship (since it has a constant rate of $22 per t-shirt), into a non-proportional graph with the same y-intercept as the second business (which has a fixed setup fee), we need to adjust the price so that it includes a fixed cost but still retains the same y-intercept.
The second graph has a y-intercept of $15 (the setup fee) when the quantity of t-shirts is zero. Therefore, we need to shift the first graph down by $15 to achieve the same y-intercept.
Thus, the correct response is:
Down 15.