Hey there :)
We know the volume formula of a rectangular prism
Volume = length × width × height
A swimming pool shares the same concept of a rectangular prism
We are given the:
Volume = 1,408 ft³
Height = 4 ft
Length = 22 ft
Width = w
Apply the formula:
1,408 = 22 × 4 × w
1,408 = 88w
Divide by 88 on either side to isolate w

16 = w
The width is 16 ft