Question

The fourth proportional to 5, 35 and x is 84, find the value of x.

• A. 294
• B. 12
• C. 588
• D. 14

Answer 1

Answer:

B. 12

The fourth proportional means:

5 : 35 = x : 84

So,

$\frac{5}{35} = \frac{x}{84}$

Simplify:

$\frac{1}{7} = \frac{x}{84}$

Now solve:

$x = \frac{84}{7} = 12$

Final Answer: x = 12