Interpreting Line GraphsInterpreting Line Graphs

Understanding the Understanding the language of line graphs.language of line graphs.

Line Graphs Express SlopeLine Graphs Express Slope• Line graphs provide an

excellent way to map independent and dependent variables that are quantitative.

• When both variables are quantitative, the line segment that connects two points on the graph expresses a slope.

• The slope of lines on a graph can be interpreted visually when looked at in relation to the slope of other lines.

Let’s Review SlopeLet’s Review Slope• The slope of a line measures the steepness of the line. • Most of you are probably familiar with associating slope with "rise

over run". • Rise means how many units you move up or down from point to

point. On the graph that would be a change in the y values. • Run means how far left or right you move from point to point. On

the graph, that would mean a change of x values.

What do these lines mean at a What do these lines mean at a glance?glance?

What would it look like?What would it look like?• Draw a quick graph displaying distance y (mi)

as a function of time x (hrs). Don’t worry about making it perfect according to the rules this time.

• Mrs. Goble’s dog leaves her house to chase a squirrel.• The dog gets tired and decides to take a nap under a tree in

the woods.• The dog wakes up and goes to the neighbors house to get in

the trash.• After getting ran-off the dog goes back home to get in his

own trash.

Understanding Graphing VerbsUnderstanding Graphing Verbs When we

interpret graphs there are verbs

that are commonly used to describe rise

over run. Understanding them helps us

interpret graphs.

Use a dictionary to find the meaning of the following verbs:

plummet increase peak

soar rocket

fluctuate drop

level out decrease

decline rise fall

Write the answer to these questions Write the answer to these questions while discussing with an elbow while discussing with an elbow

partner.partner.1. Which 5 verbs mean go up?2. Of these, which 3 mean go up suddenly/a lot?3. Which 5 verbs mean go down?4. Which verb means reach its highest level?5. Which verb means stay the same? 6. Which verb means go up and down?7. Which verbs are associated with rise and which

with run?

Now decide which parts of the graph below, Now decide which parts of the graph below, showing the book sales of a book between 1990 and showing the book sales of a book between 1990 and 2000, can be described using the verbs you defined.2000, can be described using the verbs you defined.

Interpretation can also be made in more Interpretation can also be made in more detail by modifying a detail by modifying a verbverb with an with an adverbadverb..

• Using the same graph as before on the sales of a book from1990-2000, make sentences describing the changes represented from month to month using verbs and adverbs.

1. 1990 – 19922. 1992 – 19943. 1994 – 19974. 1997 – 2000

Adverbs:slightly slowly sharplyrapidly steadily gradually moderately dramatically

Create sentences using verbs and Create sentences using verbs and adverbsadverbs

1. 1990 – 19922. 1992 – 19943. 1994 – 19974. 1997 – 2000

Adverbs:slightly slowly sharplyrapidly steadily gradually moderately dramatically

Knowing graphing vocabulary helps you understand what the graph is trying tell you in when it’s picture

form.

Create Your Own GraphCreate Your Own Graph

• Using the data provided create a line graph.• Be sure that you have followed all the line

graphing rules.• When your line graph is completed, write a

paragraph interpreting what the graph is displaying with words. Use both verbs and adverbs.

• Be ready to share out with the class.