The graph shows profit on the vertical (y) axis, and number of shirts on the horizontal (x) axis. The negative y-intercept means Benito's "profit" was a loss of $20 before he sold any T-shirts. The x-intercept shows the number of shirts Benito had to sell to break even (have zero profit). Benito can only sell zero or some positive <em>integer</em> number of T-shirts. Thus the true statement in part A is ...
... C. The x-intercept represents the shirts he has to sell before making a profit.
The graph shows profit from sales of the first 11 T-shirts sold. After selling 11 shirts, Benito had a profit of $70, or about $6.36 per shirt, on average. The graph shows an increase in profit of $10 for each shirt in the first 7, and an increase in profit of $15 for each shirt after that. The true statement in Part B is ...
... D. Benito's profit per shirt increases from $10 to $15.
