Question

Determine if the following numbers are in proportion or not:

(3) 10, 8, 6, 4
$$\begin{gathered} 5:x=20:24 \\ \Rightarrow \frac{5}{x}=\frac{20}{24} \\ \Rightarrow x\times 20=5\times 24 \\ \Rightarrow 20x=120 \\ \Rightarrow x=\frac{120}{20} \\ \Rightarrow x=\frac{6}{1} \\ \Rightarrow x=6 \end{gathered}$$

Answer 1

Consider the ratio of 10 and 8.
$10:8=\frac{10}{8}=\frac{10÷2}{8÷2}=\frac{5}{4}$

Now, consider the ratio of 6 and 4.
$6:4=\frac{6}{4}=\frac{6÷2}{4÷2}=\frac{3}{2}$

The two ratios are unequal.
If two ratios are unequal, then the values or numbers are not in proportion. So, the numbers 10, 8, 6 and 4 are not in proportion.