Last month, a 730 g box of cereal was sold at a grocery store for $3.00. However, this month, the cereal manufacturer launched the same cereal in a 560 g box, which is being sold at $2.40. What is the percent change in the unit price?
First, find out the unit price of each box as follows:
$3 or 300 cents / 730 grams =0.410959 cents per gram - This is the first box.
$2.40 or 240 cents / 560 grams =0.428571 cents per gram - This is the second box.
As you can see, there is an increase in the unit price of the 2nd box over the 1st box by:
0.428571 / 0.410959 =1.04286 - 1 =0.04286 x 100 =4.286% increase, or overall change in unit price.