Question

$$\begin{array}{ccccc}X& 2& 4& 5& 50\\ Y& 4& 8& 10& 100\end{array}$$

If $x$ and $y$ are directly proportional, find the value of constant of proportionality.

• A. $\frac{1}{2}$
• B. $\frac{3}{4}$
• C. $\frac{4}{3}$
• D. $\frac{5}{2}$

Answer 1

The correct option is A

$\frac{1}{2}$

Given $X$ and $Y$ are directly proportional. So $\frac{X}{Y}$ is constant. This constant is also known as the constant of proportionality.

The corresponding values of X and Y will have a constant value for $\frac{X}{Y}$. Now, if we take X = 2 and Y = 4, we get the constant of proportionality as $\frac{X}{Y}=\frac{1}{2}$.