In a single-slit diffraction pattern, the central fringe is 420 times as wide as the slit. The screen is 17,000 times farther from the slit than the slit is wide. What is the ratio /W, where is the wavelength of the light shining through the slit and W is the width of the slit? Assume that the angle that locates a dark fringe on the screen is small, so that sin(theta) is approximately equal to tan(theta) .