Can someone answer. there is a picture. there is only one question. you so much

Look at attachment. has all info needed. need

Last month, a 770 g box of cereal was sold at a grocery store for $3.10. however, this month, the cereal manufacturer launched the same cereal in a 640 g box, which is being sold at $2.50. what is the percent change in the unit price?

Plot the intercepts to graph the equation