## Basic College Mathematics (10th Edition)

Ans: $x=25$
$\frac{5}{9} = \frac{x}{45}$ We need to find the unknown Number in the proportion. First we need to find the cross product i.e. $5\times45 = x \times 9$ So, $9 x = 225$ Divide both sides by 9 i.e. $9 x \div 9 = 225 \div 9$ so, $x=25$