Pie Charts
Another common graph used for displaying the distribution of categorical data is a pie chart. Pie charts are a way to display categorical data when you want to compare parts of a whole.
pie chart
Pie charts display data in a round graph split into “pie pieces” or “wedges” in a circle.
Each piece represents the proportion of the quantity or frequency of individuals or items in each category. Basically, pie charts display the relative frequencies of your data set and all pieces should add to be [latex]100[/latex]%.
A key is provided to identify the categories associated with each relative frequency. Pie charts are useful for visually comparing relative frequencies.
Sleep Study: Pie Charts
STEP 1: Select the “One Categorical Variable” tab.
STEP 2: Locate the dropdown under “Enter Data and select “From Textbook.”
STEP 3: Click on the dropdown menu for “Data Set“ and choose “Sleep Study – Lark vs. Owl.”
STEP 4: Scroll down to “Additional Plots” and select the “Pie Chart” option. The pie chart will appear below the bar graph.
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STEP 1: Select the “One Categorical Variable” tab.
STEP 2: Locate the dropdown under “Enter Data” and select “Frequency Table.”
STEP 3: Enter “3” for “Number of Categories.”
STEP 4: In the box under “Name of Variable,” type Anxiety Status.
STEP 5: Enter the labels for the three anxiety levels and their respective numbers observed in the Sleep Study.
STEP 6: Scroll down to locate “Additional Plots” and select “Pie Chart.”