I want to put the actual data on a bar graph.

Prism does not offer any way to automatically include the mean, median, sample size (n), or any other value over bars. Nor does it offer an automatic way to include asterisks over pairs of bars to denote statistical significance.  

Instead, you can copy an block of data (or a single value) from either a data or results table and paste those values (or that value) onto the graph. Prism will maintain a live link, updating the value(s) if the data change.

After pasting, drag into position.  Note that Prism 5 makes it easy. When the text is centered over a bar, or a group of bars, it will snap into place.