Have you ever thought about temperature? Or about how to measure and display data about temperature? Take a look.
Eleanor Roosevelt School recorded the daily indoor and outdoor temperature for a period of five days. What conclusions can you draw from the graph below of the data?
This Concept is about multiple line graphs. Use this Concept and then you will know how to answer this question about temperature at the end of the Concept.
Guidance
Recall that a line graph displays changes in data over time. A multiple line graph displays changes in two or three sets of data over time.
Now let’s look at some situations where we can create multiple line graphs and then interpret the data displayed on them.
Full-time and part-time enrollment at California State University for the past five years is recorded on the data table below. Create a multiple line graph to represent the information on the data table.
Year: | Number of Students Attending Full-Time: | Number of Students Attending Part-Time: |
---|---|---|
2003 | 10,000 | 2,000 |
2004 | 9,500 | 2,100 |
2005 | 11,100 | 2,050 |
2006 | 12,000 | 2,700 |
2007 | 13,300 | 2,550 |
To create a multiple line graph:
- Draw the horizontal \begin{align*}(x)\end{align*} and vertical \begin{align*}(y)\end{align*} axis.
- Give the graph the title “Enrollment at California State University.”
- Label the horizontal axis “Year.”
- Label the vertical axis “Enrollment.”
- Look at the range in data and decide how the units on the vertical axis \begin{align*}(y)\end{align*} should be labeled. In this case, label the vertical axis 0 – 14,000 by thousands.
- Use one color pen to plot the data for full-time students first. For example, for the year 2003, place a point at 10,000. For the year 2004, place a point between 9,000 and 10,000 to show that the enrollment was 9,500. As you continue to plot the enrollment for each year, use a straight edge to connect the points.
- Use another color pen to plot the data for part-time students. For the year 2003, place at point at 2,000. For the year 2004, place a point slightly above 2,000 to show that the enrollment for that year was 2,100. As you continue to plot the enrollment for each year, use a straight edge to connect the points.
Looking at the line graphs, what can you conclude about enrollment at California State University?
You can see that the number of full-time students enrolled increased by 3,300 students from 2003 to 2007. While full-time enrollment declined between 2003 an 2004, it increased every other year. The number of part-time students enrolled increased by 550 students from 2003 to 2007. It is apparent that the increase in full-time enrollment was greater than the increase in part-time enrollment.
Now answer the following questions about multiple line graphs.
Example A
True or false. A multiple line graph would be useful in showing how data changes from year to year.
Solution: True.
Example B
True or false. You could use a multiple line graph to show how attendance at school changed from one year to the next for two or three grades of students.
Solution: True.
Example C
True or false. You can use multiple line graphs to show data that is not related.
Solution: False. There must be a relationship to show how the data changes over time and how it can be compared.
Here is the original problem once again.
Eleanor Roosevelt School recorded the daily indoor and outdoor temperature for a period of five days. What conclusions can you draw from the graph below of the data?
The results of the data collection are presented on the double line graph below. Looking at the graph, you can see that the indoor temperature was cooler than the outdoor temperature. It can also be concluded that as the outdoor temperature decreased, the indoor temperature decreased. The same holds true as the temperature increased.
Guided Practice
Here is one for you to try on your own.
Use the following line graph to answer each question.
What is being measured in this line graph? What was the highest temperature recorded? What was the lowest temperature recorded?
Answer
This line graph measures how temperature changes from February 1st to February 7th.
The highest temperature was 33 degrees on February 3rd.
The lowest temperature was 26 degrees on February 5th and 6th.
Video Review
This is a Khan Academy video on line graphs.
Explore More
Directions: The table below shows the number of tickets sold at the Phoenix Zoo and the Seattle Zoo since 1998.
1. Create a multiple line graph using the data from the table.
Year: | Number of Tickets Sold at Phoenix Zoo: | Number of Tickets Sold at Seattle Zoo: |
---|---|---|
1998 | 547,000 | 601,000 |
1999 | 562,000 | 602,500 |
2000 | 569,000 | 603,700 |
2001 | 566,000 | 605,000 |
2002 | 569,000 | 604,000 |
2003 | 572,000 | 605,100 |
2004 | 576,000 | 606,000 |
2005 | 575,500 | 605,800 |
2006 | 579,000 | 607,000 |
2007 | 580,000 | 608,000 |
2. Which zoo sold more tickets in 2003?
3. Which zoo sold more tickets in 2005?
4. Which was the best year for sales at the Phoenix zoo?
5. Which was the best year for sales at the Seattle zoo?
6. Based on this information, can we say which zoo is more popular? Why?
7. Based on this data, will sales increase or decrease in 2008 at the Phoenix zoo?
8. Based on this data, will sales increase or decrease in 2008 at the Seattle zoo?
9. What is the difference in the quantity of tickets in 2005?
10. What is the difference in the quantity of tickets in 2000?
Directions: The data table below depicts the increase in cost of a movie ticket each year since 2000.
Year: | Price of a Ticket: |
---|---|
2000 | $5.50 |
2001 | $5.75 |
2002 | $6.00 |
2003 | $6.25 |
2004 | $6.50 |
2005 | $7.25 |
2006 | $8.00 |
2007 | $9.25 |
11. Decide which type of graph, bar or line should be used to represent the information in the data table.
12. Then use the information on the data table to create the graph you’ve chosen.
13. True or false. A multiple line graph is the best choice for this data.
Directions: The data table below depicts the number of newspapers in circulation (in millions) over a period of three days.
14. Decide which type of graph, bar or line should be used to represent the information in the data table.
15. Then use the information on the data table to create the graph you’ve chosen.
Name of Newspaper | Friday | Saturday | Sunday |
---|---|---|---|
Los Angeles Times | 55 | 58 | 60 |
New York Times | 62 | 63 | 67 |
Chicago Sun | 47 | 49 | 49 |
Orange County Register | 39 | 41 | 42 |
San Francisco Chronicle | 51 | 53 | 55 |