The amount of space inside the phone booth can be calculated by finding the volume of the booth, which is the product of its length, width, and height.
Given:
Length = 3 ft
Width = 4 ft
Height = 7 ft
To find the volume of the phone booth:
Volume = Length x Width x Height
Volume = 3 ft x 4 ft x 7 ft
Volume = 84 ft³
Therefore, the correct amount of space inside the phone booth is 84 ft cubed.