When you edit data, Prism automatically recalculates the analyses and updates the graphs.
Freeze a results or graph sheet if you don't want it to update. For example, you might want to freeze results and a graph before excluding some outliers from the data. You can then repeat the analysis, and have both copies of the results and graphs in the project. Note that Prism doesn't let you freeze data tables, info sheets, or layouts.
Click the Freeze button in the Sheet section of the Prism toolbar to freeze a results sheet or graph. The Prism bottom toolbar will indicate that the sheet has been frozen and won't update with any changes to the data. Click again to unfreeze.