.GRA File Extension
What is a GRA file?
Graph or chart created by Microsoft Graph, a program included with Microsoft Office; may be generated within Microsoft Word, Excel, or PowerPoint; most often created from Excel spreadsheet data.
Graphs can be created in Microsoft Word by selecting Insert→Picture→Chart.... In Excel, first select a group of data, then choose Insert→Chart.... In PowerPoint, simply select Insert→Chart... and enter the data into the Datasheet window that pops up.