A Young’s double-slit setup initially produces a fringe width β0 with slit separation d0, screen distance D0, and light of wavelength λ0. The arrangement is then modified as follows:
• The screen is moved 25% closer to the slits.
• The light source is replaced by one of wavelength 1.1λ0.
• The slit separation is reduced by 20%.
Calculate the ratio of the new fringe width to the original fringe width (βnew/β0).