Question

In a proporation, the first, second and fourth terms are 7, 42 and 72 respectively. Find the third term

Answer 1

Answer:

The third term of the proportion is $12$.

Step-by-step explanation:

Given : In a proportion, the first, second and fourth terms are $7$, $42$ and $72$ respectively.

To find : The third term of the proportion =?

Solution :

• It is given that in a proportion, the first, second and fourth terms are $7$, $42$ and $72$ respectively.
• i.e. $7:42::?:72$
• We have to find the third term of the proportion.
• Let,  $x$ be the third term of the proportion.

• We can rewrite the proportion as follows,

      $\frac{7}{42} =\frac{x}{72}$

• By cross multiplication, we get

     ∴  $7*72=42x$

        ∴ $42x =504$

           ∴ $x=\frac{504}{42}$

           ∴ $x=12$

• ∴ The third term of the proportion is $12$.

Answer 2

Answer:

If in a proportion, the first, second and fourth terms are 7, 42 and 72 respectively then the third term is 12.

Step-by-step explanation:

If the third term is x

Then 7,42,x,72 are in proportion

$\frac{7}{42} =\frac{x}{72} \\42x = 7 \times 72\\x = \frac{7 \times 72}{42} \\x=\frac{72}{6} \\x = 12$

So the third term is 12.