A closed rectangular box having a volume of 7 ft3 is to be constructed. If the material for the sides costs $1.2/ft2 and the material for the top and...

A closed rectangular box having a volume of 7 ft3 is to be constructed. If the material for the sides costs $1.2/ft2 and the material for the top and bottom costs $1.3/ft2, find the dimensions of the box that can be constructed with minimum cost. (Give your answers correct to 2 decimal places.)