LINE GRAPH

By Cassidy Abdalla, Chloe Withers, and Julie Byrne

Definition

A type of graph that has points connected by lines to represent how

something changes in value over time.

When to Use Line Graphs

Line graphs show changes over time and gives your data a better visual so you can see the differences between

each point as time changes.

Data

You can use a single set or multiple sets of numerical data with an

independent and dependent variable.

Example

Population is a real life example of how data changes over time.

Data CollectionTime Temperature (◦F)

8:00 AM 14

9:00 AM 16

10:00 AM 18

11:00 AM 19

12:00 AM 20

1:00 PM 21

2:00 PM 21

3:00 PM 25

4:00 PM 21

5:00 PM 20

6:00 PM 18

7:00 PM 17

8:00 PM 15

Steps1. Collect Data (can be anything numerical and over time)2. Insert data on Excel3. Highlight data and click “Insert” then “Line”4. Add axis titles and graph title 5. Make sure your independent variable is on the x-axis and your

dependent variable is on the y-axis

How to Interpret a Line Graph

If you look at the overall graph, you see the line rises and falls. When the line gets higher on the graph, it means the temperature increased.

When the line gets lower on the graph, it means thetemperature has decreased. To find the exact temperatureof a dot, you look to the left and see which number lines up with the dot. To find out the time of each temperature,you look below the dot and see which time lines up.

Problem

What is the average temperature from 8 am. to 8 pm?

19 ˚F

Advantages

• Can read and understand easily• Can quickly make• Can have multiple values for axis• Can have compare multiple sets of

data• Shows exact values

Disadvantages

• Not visually attractive• Can deceive• Only one dimensional• Only use with continual data• Hard to scale

Links from Research

• http://www.census.gov/population/international/data/idb/worldpopgraph.php

• http://www.whaqualitycenter.org