What is the percent of the area under the density curve where x is less than 4

Rectangle leg this 11feet and perimeter of 38feet what is the width of the rectangle in feet

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?

Anyone? 15m is what percent of 60m; 3m; 30m; 1.5 km?