$.$ When a laser is directed toward a plate with two slits that are $0\mathrm{.}3$ mm apart, the interference fringes on a screen that is $1\mathrm{.}5$ m away are $3\mathrm{.}2$ mm apart. If the entire apparatus $($laser$,$ plate, and screen$)$ is placed under water, how far apart will the interference fringes be$?$