How to crop photo X1.5 in Adobe Photopshop?

I have photos of Nikon FX camera and i whant to crop that photo X1.5 to see how will look that pic. On DX camera.

I don't see the point? You can have the exact same photo on either the FX or DX sensor camera. The difference is that with the DX you will either have to move back further or use a wider focal length on the lens. The ASPECT RATIO of the two sensors are IDENTICAL, so you can get the exact same composition of a scene with either camera, again, only your position or the lens focal length will have to be different between the two cameras.