set up and label the proportion

A 6 ft tall ten standing next to a cardboard box casts a 9 ft shadow. If the cardboard box casts a shadow that is 6 ft long then how tall is it?

3 answers

6/9 = x/6

Solve for x.
Help!!! Idk
is 1/4 or 10/17.5 a proportion or not a proportion.