Question

Complete this proportion:
$\dfrac{7}{{21}} = \dfrac{4}{?}$

Answer 1

Hint: We will use the concept of proportions to find the value of the unknown term.

Complete step by step answer:
Now the proportion statement given to us is:
$\dfrac{7}{{21}} = \dfrac{4}{?}$
So we can simplify the left hand side to get $\dfrac{7}{{21}} = \dfrac{1}{3}$.
And now $\dfrac{1}{3} = \dfrac{4}{?}$, so we will now divide both sides by 4 to make it proportional and we will get $\
   \Rightarrow \dfrac{1}{{3 \times 4}} = \dfrac{1}{?} \\
   \Rightarrow \dfrac{1}{{12}} = \dfrac{1}{?} \\
\ $
Now comparing both sides by taking the reciprocal we will get:
$\
   \Rightarrow 12 = ? \\
  or,? = 12 \\
\ $

Hence the missing value in the proportion is 12.

Note: Since it’s a proportion so the left hand side should be simplified correctly in order to get equated with the right hand side.