Question

Solve the proportion

$\frac{a}{9}=\frac{21}{27}.$

Short answer

The solution of the given proportion is $a=7$.

Step-by-step solution

Step 1.  Given

The given proportion is$\frac{a}{9}=\frac{21}{27}.$

Step 2.  To determine

We have to solve the proportion$\frac{a}{9}=\frac{21}{27}.$

Step 3.  Calculation 

Solve the given proportion.

$\begin{array}{c}\frac{a}{9}=\frac{21}{27}\\ \frac{a}{9}\cdot 9=\frac{21}{27}\cdot 9\left[\text{multiplyeachsideby}9\right]\\ a=\frac{189}{27}\left[\text{simplify}\right]\\ a=7\left[\text{divide}\right]\end{array}$

So, the solution is $a=7$.