Two slits spaced $0\mathrm{.}0720$ mmmm apart are $0\mathrm{.}800$ mm from a screen. Coherent light of wavelength passes through the two slits. In their interference pattern on the screen, the distance from the center of the central maximum to the first minimum is $3\mathrm{.}00$ mmmm$.$ The intensity at the peak of the central maximum is $0\mathrm{.}0400$ W$/$m$2$W$/$m$2.$