Question

The proportionality constant for the given graph is .

• A. 15
• B. 20
• C. 30

Answer 1

The correct option is C 30


We observe that as the $x$-value increases, so does the $y$-value. So, the given graph represents an indirect variation.

An indirect variation is represented as:
$y\propto \frac{1}{x}⟹y=\frac{K}{x},$ where $K$ is the proportionality constant.

Putting the values from the given graph in the equation, we get:

Value of $x$	Value of $y$	$x\times y$	$K=x\times y$
2	15	$2\times 15$	30
5	6	$5\times 6$	30
6	5	$6\times 5$	30
10	3	$10\times 3$	30

$\therefore K=30$

∴ The proportionality constant is 30.