Representative Problem

The line graph shows the number of picture frames a workshop made each month. In July the workshop made $80$ more frames than it made in June, and the number of frames made in July and August together is $640$. Complete the line graph.

(Figure) A line graph titled "Picture Frames Made." The horizontal axis shows the month the count was taken — $4$ (April), $5$ (May), $6$ (June), $7$ (July), and $8$ (August). The vertical axis shows the number of frames, with major gridlines at $0$, $100$, $200$, $300$, and $400$ and each small grid square worth $20$ frames. Points are plotted and joined for April at $280$, May at $380$, and June at $180$; the points for July and August have not yet been plotted.