7.5. Pie Charts http://www.ck12.org
Step 4:Graph each section. Write the name and correct percentage inside the section. Color each section a different
color.
The above pie chart was created by using a hundreds disk, which is a circle with 100 divisions in groups of 5. Each
division (line) represents 1 percent. From the graph, you can see that more donations were of Type O than any other
type. The fewest number of donations of blood collected was of Type AB. If the percentages had not been entered
in each section, these same conclusions could have been made based simply on the size of each section.
Example B
Construct the pie chart in Example A by using a circle instead of a hundredths disk.
Step 1:Determine the total number of donors: 7+ 5 + 9 + 4 =25.
Step 2: Express each donor number as the number of degrees of a circle that it represents by using the formula
Degrees=nf· 360 ◦, wherefis the frequency andnis the total number.
7
25
· 360 ◦= 100. 8 ◦
5
25
· 360 ◦= 72 ◦
9
25
· 360 ◦= 129. 6 ◦
4
25
· 360 ◦= 57. 6 ◦
Step 3:Using a protractor, graph each section of the circle.
Step 4:Write the name and correct percentage inside each section. Color each section a different color.