Question

Find the value of x in each of the following proportion:​
(v)$5:15=4:x$

Answer 1

The given value proportion can be calculated for the value of $x$ as follows
$5:15=4:x$
$\Rightarrow$ $\frac{5}{15}=\frac{4}{x}$
$\Rightarrow 5\times x=4\times 15$
($\because$ $\text{Product of extremes = Product of means}$)

$\Rightarrow x=\frac{4\times 15}{5}=\frac{4\times (5\times 3)}{5}$

$\therefore x=4\times 3=12$

Hence , the value of $x$ $\text{is}$ $12$.