In the following proportion, write their means and extremes.

$5:3::20:12$

In the following proportion, write their means and extremes.

$\frac{1}{2}:\frac{3}{4}::\frac{5}{10}:\frac{15}{20}$

In the following proportion, write their means and extremes.

$2:16::8:64$

In the following proportion, write their means and extremes.

$a:c::b:d$

In the following proportion, write their means and extremes.

$9:10::x:y$

In the following proportion, write their means and extremes.

$p:q::7:8$

In the following proportion, write their means and extremes.

$l:m::n:p$

In the following proportion, write means, extremes, product of means and product of extremes.

In the following proportion, write means, extremes, product of means and product of extremes.