Q60.

BASIC SKILL

Use cross products to solve each proportion.

60. $\frac{4}{20} = \frac{1}{m}$

Verified

Answer

Given proportion is simplified to $m = 5$

1Step 1 - Cross product between two proportions

Let $\frac{a}{b}$ and $\frac{c}{d}$ be two equal proportions that is $\frac{a}{b} = \frac{c}{d}$

Then cross product is defined as multiplication of denominator of one proportion with the numerator of other proportion, that is $a d = b c$

2Step 2 - Substitution

Substitute 4 for a, 20 for b, 1 for c, and m for d into $a d = b c$ gives

$4 \times m = 20 \times 1$

3Step 3 - Simplify 4 × m = 20 × 1

To simplify this expression multiply both the numbers of right side and then divide it from number on the left as shown below

\begin{matrix} 4 m = 20 \\ m = \frac{20}{4} \\ m = 5 \end{matrix}