we are given dimensions of the sketch :
length = 12 inches.
width = 18 inches.
given scale factor = 0.2.
the actual dimensions of the mural would be: the sketch dimensions divide by scale factor.
(because the mural would be larger than the sketch dimensions).
we need to find the actualy length of the mural.
therefore,
the length of the mural = 12 inches ÷ 0.2 = 60 inches.
therefore, the correct option is third option that is 60 inches.