Using the equation for the distance between fringes,

$$y $=$

x$$d

$,$

complete the following.

$($a$)$

Calculate the distance $($in cm$)$ between fringes for $488$ nm light falling on double slits separated by $0\mathrm{.}0450$ mm$,$ located $3\mathrm{.}20$ m from a screen.

cm

$($b$)$

What would be the distance between fringes $($in cm$)$ if the entire apparatus were submersed in water, whose index of refraction is $1\mathrm{.}333?$

cm