A proportional relationship exist between 2 variable where the ratios are similar or equivalent. A proportional relationship always has a constant value which is also called constant of proportionality . In a table to recognise if it is proportional we write those 2 variables as a fraction and reduce them . There after you compare them to see if the ratios or reduced fractions are equivalent.
Example of a table that depicts proportionality is represented below
The table represent x and y value which are 2 variable now let us check if the table above exhibit proportionality.
let us take the ratios of the x and y values and see if the reduced ratio is same for all x and y value in the table.
[tex]\begin{gathered} \frac{x}{y} \\ \frac{4}{6}=\frac{2}{3}=2\colon3 \\ \frac{6}{9}=\frac{2}{3}=2\colon3 \\ \frac{8}{12}=\frac{2}{3}=2\colon3 \\ \frac{10}{15}=\frac{2}{3}=2\colon3 \\ \frac{14}{21}=\frac{2}{3}=2\colon3 \end{gathered}[/tex]
Notice that the ratio of x to y is the same through out the table. This shows proportionality.
To notice a proportionality on a graph, the graph forms a straight line that run through the origin. example of such graph is
Note we used the value from the table to draw the graph.
