In the proportion 5/6=10/12 , the means are . 5 and 12
5 and 10
6 and 12
6 and 10

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?