Question

the fourth promotional of 5 8 15 is ​

Answer 1

Question:-

the fourth promotional of 5 8 15 is _______.

Answer:-

• The fourth proportional is 24.

Solution:-

• Let the fourth proportional be x

$\large{\tt:\implies\: \: \: \: \: \: \: \: {}5 : 8 : : 15 : x}$

$\large{\tt:\implies\: \: \: \: \: \: \: \: {} \frac{5}{8} = \frac{15}{x} }$

After cross multiplication,

$\large{\tt:\implies\: \: \: \: \: \: \: \: {}5 \times x = 15 \times 8}$

$\large{\tt:\implies\: \: \: \: \: \: \: \: {}x = \frac{15 \times 8}{5} }$

$\large{\tt:\implies\: \: \: \: \: \: \: \: {}x = 3\times 8}$

$\large{\tt:\implies\: \: \: \: \: \: \: \: {}x = 24}$

• The fourth proportional is 24.