Answer: 3.76 mm
Explanation: The formulae that defines the position of a nth fringe from the center of a double slit interference experiment is given below as
y =R×mλ/d
Where y = distance between the nth fringe and the center
R = distance between slits and screen = 1.71 m
m = position of fringe = 1
d = distance between slits = 0.254 mm = 0.000254m
λ = wavelength of light = 559 nm = 559×10^-9m
By substituting parameters, we have that
y = 1.71×1×559×10^-9/0.000254
y = 0.00000095589 / 0.000254
y = 0.00376m = 3.76 mm
