Two narrow slits are used to produce a double-slit interference pattern with monochromatic light. The slits are separated by 4 mm, and the interference pattern is projected onto a screen 8 m away from the slits. The central bright fringe is at a certain spot on the screen. Using a ruler with one end placed at the central fringe, you move along the ruler passing by two more bright fringes and find that the next bright fringe is 24 mm away from the central fringe. What is the wavelength of the light? (Show your work).