1. The problem statement, all variables and given/known data A double-slit interference pattern is created by two narrow slits spaced 0.21mm apart. The distance between the first and the fifth minimum on a screen 60cm behind the slits is 6.2mm. What is the wavelength of the light used in this experiment? 2. Relevant equations gamma = d/L * Delta y 3. The attempt at a solution delta y = 6.2mm/5 = 1.24*10 ^-3m gamma = d/L delta y = (2.1*10^-4m)/0.6m * 1.24*10^-3 = 434nm but this is incorrect. Where did I go wrong?