Question

A bottle of water costs $\$1.50$.

Explain how you would make a graph of four ordered pairs to model the total cost of the water in terms of the number of bottles.

Answer 1

Step-1: Form an equation for the graph:

Let the total cost of the water bottle be $y.$

Let the number of water bottles be $x.$

cost of each bottle is $\$1.50$.

The equation becomes:

$y=\$1.50\times x$

Step-2: find different values of $y$ for different values of $x$ to get ordered pairs

$$\begin{gathered} \mathrm{If}x=1, \\ y=\$1.50;(1,1.5) \\ \mathrm{If}x=2, \\ y=\$3.00;(2,3) \\ \mathrm{If}x=3, \\ y=\$4.50;(3,4.5) \\ \mathrm{If}x=4, \\ y=\$6.00;(4,6) \end{gathered}$$

By Continuing the more values of $x.$, more values of $y$ can be calculated.

Hence, the required ordered pairs are $(1,1.5),(2,3),(3,4.5),(4,6)$.