Question 294190
When working with proportions like this, always remember:
{{{ a/b = c/d }}} Cross multiply and you will find that ad = bc <br>
Now we will set this up using your data:
{{{ z/7 = 16/56 }}} cross multiplying gives us:
{{{ 56z = cross(7*16) = 112 }}} <br>
Divide both sides by 56: 
{{{ 56z/56 =  112/56 }}}
and we find that 
z = 2 
and bob's your uncle!