Question

Paulina’s income from a job that pays her a fixed amount per hour is shown in the graph. Use the graph to find the total income earned for working four 8-hour days all at the standard rate.

Answer 1

We need to find the equation of an income y at any time x

Using two-point formula

`(y-y_1)/(x-x_1)=(y_2-y_1)/(x_2-x_1)`

At points (1, 10) and (6, 60)

`\begin{gathered} \Rightarrow(y-10)/(x-1)=(60-10)/(6-1)=(50)/(5)=10 \\ \\ \Rightarrow(y-10)/(x-1)=10 \\ \\ \Rightarrow y-10=10x-10 \\ \\ \Rightarrow y=10x \end{gathered}`

Four 8 hours = 8 + 8 + 8 + 8 = 32

At x = 32 => y = 10 × 32 = 320

Therefore, the total income for working four 8 hours is $320