#### Find the missing number in the box $--$ in each of the proportions:$\frac{8}{--}=\frac{3.2}{4}$

Assume the missing number is x.
$\frac{8}{x} = \frac{3.2}{4}$

$x =\frac{8}{3.2} \times 4 = 10$

Hence, the missing number in box is 10.