  ### Home > GB8I > Chapter 9 Unit 3 > Lesson CC3: 9.2.1 > Problem9-64

9-64.

Use the graph at right to answer the following questions. Homework Help ✎

1. What kind of growth does this graph show? How do you know?

Does the graph show linear growth or non-linear growth? You can tell because linear growth creates a line.

2. What is this graph describing? Write an appropriate title for the graph.

Look at the $x$-axis and $y$-axis labels. The graph shows the distance from home at several different time periods.

Possible title: Distance and Time

3. How far from home is the person when the graph starts?

The graph starts at $0$ hours. Which means this person just started to travel. What is the distance from home at $0$ hours?

He starts at $9$ miles from home.

4. How fast is the person traveling? Explain how you can use the graph to determine the rate of travel.

Find the slope of the line.

$\text{Find the }\frac{\text{rise}}{\text{run}}.$

$\frac{10}{4} = 2.5\text{ miles per hour}$

5. Write an equation to represent the line on the graph.

A slope of $2.5$ means that the distance from home increases $2.5$ miles per hour. That means we multiply $2.5$ and any hour which we will call $x$.

Since we know how fast this person is traveling, we also need to know the starting distance. From part (b) we found that this person started $9$ miles away from home.

$y = 2.5x + 9$
$2.5$ relates to amount traveled every hour and $9$ relates to the starting point. 