Using proportions, it is found that a tree that casts a shadow 4 ft long is 180 in. tall.
A proportion is a fraction of a total amount, and the measures are related using a rule of three.
In this problem, a fire hydrant that is 30 in. tall and casts a shadow 8 in. long. We want to find the height of a tree that casts a shadow of 4 ft = 4 x 12 = 48 inches. Hence, the rule of three is given by:
30 in - 8 in
h in - 48 in
Applying cross multiplication:
h = 48 x 30/8
h = 6 x 30.
h = 180 in.
More can be learned about proportions at https://brainly.com/question/24372153