The mode is the most common number in any sample. If there is a tie, more than one mode is listed. Most people use the mode with numbers that describe categories such as types of soda or favorite sports. The mode indicates which category is the most popular. To calculate the mode by hand, count the number of votes for each category. When data gets to be too large to count by hand, use a statistical program like Minitab to calculate the mode.
Install Minitab and open the program by selecting it from the "Start" menu in Windows. When Minitab opens, a worksheet will display. For this example, there are eight types of chocolate bars that people are being asked to taste, selecting their favorite.
Label the first column (C1) "Favorite" and enter your numbers in this column. For this example, use 7, 8, 3, 4, 6, 7 and 7. Notice that you do not have to enter the numbers in any particular order.
Select the "Stat" option among the headers at the top of Minitab. Choose the "Basic Statistics" sub-option and select the "Display Descriptive Statistics" option. A box will open. Notice that the words “C1 Favorite” appear in the data list. Double-click this column and Minitab will select the data column “Favorite” and insert this word in the “Variables” box.
Click on the “Statistics” button and the “Display Descriptive Statistics – Statistics” box will open. Click on the box to the left of the word "Mode." Minitab will then return to the Display Descriptive Statistics box. Click “ok” and Minitab will calculate the Mode.
Read the output, which displays in the session window. Minitab reports the date and time of the analysis followed by headers and numbers. The header "Variable Name" lists the name of the column of data you input into the spreadsheet. For this example, the name of the column is “Favorite." The "Mode" heading is the actual value Minitab calculated for the mode. In this example, the mode is 7. The N for the Mode heading is the count of the most frequently occurring value; in this example, the value is 3, meaning three people preferred chocolate bar number 7.
Interpret the results. In this example, most of the people preferred chocolate bar number 7. You can have more than one mode. If the people surveyed liked chocolate bar number 7 and chocolate bar number 2 equally, the data would have two modes. Both numbers would be reported by Minitab with a comma between.
Because there can be an infinite number of modes in any data set, the mode is not very useful when describing data that is not categorical.
Minitab 16 was used in this analysis. Earlier versions of Minitab may have slightly different options and instructions.