Last Update: 2/3/2015
Plot your data (if you have not already) and make the graph window active, you can either use Integration gadget or Peak Analyzer.
For Integration gadget, go to Gadgets:Integrate... and click OK in the coming up dialog to bring up the yellow Region of Interest (ROI) box. Drag to position and resize the box to the area you want to calculate, then the Area and FWHM information will show up on the ROI top.
For Peak Analyzer, follow the steps below: