Question

The graph below shows the water needed for plants in a certain time.
Find the equation for the above graph.

• A. $y=1.5x$
• B. $y=1.6x$
• C. $y=1.7x$
• D. $y=1.8x$

Answer 1

The correct option is C $y=1.7x$


Consider two points on the graph, say (0,0) and (4,6.8).

We know, equation of a line passing through the origin is,
$y=mx$

We know,
$Slope\left(m\right)=\frac{Rise}{Run}=\frac{\Delta y}{\Delta x}$

∴ Slope of the line will be (m) $=\frac{\Delta y}{\Delta x}$
$\Rightarrow m=\frac{6.8-0}{4-0}$
$\Rightarrow m=\frac{6.8}{4}$
$\Rightarrow m=1.7$

So, by putting this value in the equation of the straight line, we get,
$\text{y}=1.7\text{x}$