Question

Find the value of x
0.6 : 1.5: : 3 : x​

Answer 1

The proportion of four integers a, b, c, and d can be represented as $a:b=c:d$

Here, d is called the fourth proportional to a,b and c.

So it is written as,

$=>\frac{a}{b}=\frac{c}{d}$

The given four values are:

$a=0.6, b=1.5, c=3$

Let, $d=x$

By substituting the values, we get:-

$=>\frac{0.6}{1.5}=\frac{3}{x}$

By using cross multiplication,

$=>0.6x=1.5\times 3$

$=>0.6x=4.5$

Divide both the sides by $0.6$ we get,

$=>x=\frac{4.5}{0.6}$

$=>x=7.5$

Hence, the fourth proportional is $7.5$

Answer 2

From the given question the correct answer is:

the value of x or the fourth proportional is 7.5

Given :

0.6 : 1.5: : 3 : x​

To find:

fourth proportional x

Concept used:

(product of means=product of extremes)

Solution:

we have to find the fourth proportional x

we know that,

The proportion of four integers a, b, c, and d can be represented as

a:b::c:d

and we also know that

(product of means=product of extremes)

product of mean =  bc

product of extremes=ab

so ,

1.5×3=0.6x

4.5=0.6x

x=4.5/0.6

x=7.5

hence the value of x or the fourth proportional is 7.5