In the Difference dialog box, specify the column of data that you want to analyze.
In Variable, enter a column of numeric data to calculate the differences.
In Lag, enter the number of rows to lag the data. Minitab subtracts the lagged data from the original data.
For example, an analyst records the number of customer orders per month. The analyst enters a lag of 1 to monitor the monthly variation. Minitab calculates the differences between consecutive observations and stores the differences in a new column.