Graph > Line Plot > choose Without Symbols - One Y > OK
Use to display a simple line plot.
Function: Choose a function.
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, use Multiple Variables.)
Categorical variable for X-scale grouping: Enter the column containing the categorical grouping variable that will be plotted on the x-scale.
Categorical variable for legend grouping: Enter the column containing the categorical grouping variable that will be identified by the legend.