To make the first graph, which is proportional (linear), into a non-proportional graph while keeping the same y-intercept as the second graph, you need to add a fixed amount in such a way that it will create a y-intercept different from zero.
The first graph represents the cost \(y = 12x\) (where \(x\) is the number of t-shirts), which passes through the origin (0,0). The second graph is represented by \(y = 11x + 20\), which has a y-intercept of 20.
To transform the first graph into a non-proportional graph with a y-intercept of 20, you can shift the entire graph upward by 20 units. This means you would change the equation to \(y = 12x + 20\).
So the correct transformation is:
Up 20.