$\"\"$

The word $\"\"$ x is to 4 $\"\"$ represents the expression $\"\"$ .

The word $\"\"$ as $\"\"$ means equal and its symbol $\"\"$ .

The word $\"\"$ 8 is to 16 $\"\"$ represents the expression $\"\"$ .

The word $\"\"$ x is to 4 as 8 is to 16 $\"\"$ represents the proportion $\"\"$ . $\"\"$

The proportion is $\"\"$ .

Multiply each side by 4.

$\"\"$

Cancel common terms.

$\"\"$ . $\"\"$

The value of $\"\"$ .