A78-inch tall man casts a shadow that is 54 inches long. at the same time, a nearby building casts a 48-foot long shadow. write and solve a proportion to find the height of the building.

78:54 Man and his shadow
x:48 Building and its shadow
78/54=x/48
x=(78)(48)/54
x=69.33 feet tall
The building nearby is about 69 feet tall

Height of the man : length of his shadow = 78 : 54
heght of the building : length of its shadow = x : 48

78/54 = x/48
78(48) = 54x
3744 = 54x
x = 3744/54
x = 69.33

The height of the building is approx. 69 ft.

The linear equation is: y=ax+b