Answer:
Step-by-step explanation:
This is a problem based on interference pf light waves.
wavelength of light λ = 553 nm
slit separation d = .134 x 10⁻³ m
screen distance D = 4.5 m
for fourth order bright fringe, path- length difference = 4 x λ
= 4 x 553
= 2212 nm .
= 2.212 μm