Answer
Ans : x = 325
Work Step by Step
$\frac{x}{20} = \frac{6.5}{0.4}$
We need to find the unknown Number in the proportion.
First we will multiply the right side of the proportion by 10 in both numerator and denominator.
i.e. $\frac{x}{20} = \frac{6.5\times10}{0.4\times10} = \frac{65}{4}$
Now, we need to find the cross product
i.e. $x\times 4 = 65 \times 20$
So, $4 x = 1300$
Divide both sides by 4
i.e. $4 x \div 4 = 1300 \div 4$
so, $x = 325$
