A set of numerical or non-numerical information is referred to as data. Data can be studied in a variety of ways. In this concept, you will analyse numerical data using a type of line graph.
A multiple-line graph is one way to present data. A Multiple Line Graph depicts the relationship between independent and dependent values from multiple data sets. Multiple line graphs are typically used to demonstrate patterns across time. Each data value in the graph is represented by a point on the graph connected by a line.
A multiple-line graph contains two or more lines that connect two or more sets of data points. The independent variable is listed horizontally, or x and the quantity or value of the data is listed vertically, or y. Finally, the legend, also known as the key, explains what each line represents.
Let’s learn how to create a multiple-line graph to show the relationship between multiple data sets using an example for better understanding.
How to Create a Multiple Line Graph
Let’s look at an example.
The data table below shows full-time and part-time enrollment at California State University during a five-year period. Let’s learn the steps to create a multiple-line graph to represent the information in the table below.
|
Year: |
Number of Students Attending Full-Time: |
Number of Students Attending Part-Time: |
|
2005 |
9,500 |
2,700 |
|
2006 |
10,000 |
2,100 |
|
2007 |
11,100 |
2,550 |
|
2008 |
13,300 |
2,000 |
|
2009 |
12,000 |
2,050 |
- Draw the horizontal (x) and vertical (y) axis first.
- The horizontal axis will be labelled as the independent variable. The independent variable, in this case, is “Year.”
- The vertical axis should then be labelled. The dependent variable is listed on the vertical axis, and the quantity of data is represented on the horizontal axis. The dependent variable, in this case, is the number of students, and the label will also be “Number of Students.”
- Next, give the graph a title. The graph’s title should be brief and to the point. It should describe the data displayed in the graph. The title, in this case, will be “Enrollment at California State University.”
- Then, on the vertical axis, decide the units. Begin by looking at the table’s smallest and largest values. The smallest and biggest values are 2,000 and 13,300. Label the vertical axis from 0 to 14,000 based on these values. Because the values are whole integers and are very evenly distributed, a unit of 1,000 can be utilised. As a result, the vertical axis will begin at 0 and progress to 14,000 in intervals of 1,000.
- After that, draw the data points. Write the years along the horizontal axis, leaving space between each one. Each year, two points will be assigned to represent the number of students enrolled part-time and full-time.
To begin, mark a point part-time students in 2003. Find 2003 on the horizontal axis and go up until you reach 2,000, then draw a point. Then, for the full-time students, draw a line. Find 2003 on the horizontal axis and move up until you reach 10,000, then draw the point. Continue drawing points for both part-time and full-time students throughout the school year.
- Next, draw the lines. Begin at the point on the far left of the graph that represents part-time students in 2003, and connect the points with a single line from 2003 to 2007. To build the second line, begin at the far left of the graph with the point representing full-time students in 2003, then connect the points with a single line from 2003 to 2007. There should be two distinct lines, each representing a different student group (part and full-time).
- Create the legend, or key, next. Each line represents a distinct student body. The legend depicts this by indicating which coloured line is for part-time students and which is for full-time students.
Now that you have your graph, discuss or analyse it by comparing lines and their respective steepness.