Graph > Boxplot > choose One Y - With Groups > OK
Use to display a boxplot with groups.
Graph variables: Enter one or more columns of data. Minitab displays a separate graph for each column. To panel all graphs on the same page, see Multiple Variables.
Categorical variables for grouping (1-4, outermost first): Enter one to four columns of grouping (categorical) variables. Minitab displays all groups on the same graph. (To panel by one or more variables, use By Variables.) The first variable is outermost on the scale and the last variable is innermost.