Easy to fix, for sure.
Next time you bring in a DXF, DWG, etc... be sure your import settings are set to inch.
To do this go to File>Import and click the 'Options' button in the Import dialog window. Slide the pulldown to 'Inches'.
You have 2 options for correcting the drawing you have:
1. If the imported geometry is a component, edit the component by double clicking, or right click and select 'Edit Component'. Once in the component measure something that you know the correct measurement for. Use the 'tape measure' tool to do this. Before doing anything else, look at the lower right of your screen. The dialog box should read what you just measured. If it is 9'6" type (without trying to put your cursor in the box) 9.5 and press enter. You will get a dialog asking you if you want to resize the component. Everything in the component will scale down to the new number.
2. If the imported geometry is not a component - simply use the 'tape measure' tool to measure a known dimension. Follow the steps above about entering the correct dimension and resize the entire model.
*Note - you can use this trick for entire models and just components - and you can use this if you start a model without regard to dimensions, like what you are working on - and need to scale it to a specific size...
