Before running the analysis of variance, you graph the means and standard errors.

To create an error bar chart, from the menus choose:

Graphs
Error Bar...

Click Define.

Select Score on training exam as the analysis variable.

Select Sales training group as the category variable.

Select Standard error of mean from the Bars Represent drop-down list.

Click OK.

Average performance clearly increases with added training days, but variation in performance decreases at the same time. ANOVA assumes equality of variance across groups; that assumption may not hold for these data.