I'm guessing definitely :) you swipe one way on floor and the other way on the tile...you should probably look it up on diy or even ask the folks at the store where you bought the tile...I am def not a pro but my pro did that to my bathroom...that's how I know...good luck :)

Start with making sure the floor is dead flat. Large format tile cannot tolerate any humps and bumps. You also have to have the right substrate, installed correctly for the type used. Then the correct MEDIUM BED MORTAR needs to be mixed and slaked, then mixed again. Not thinset. You will need a deeper notched trowel. 1/2" square notch. And yes, backbutter the tiles.

Instead of generic advice, look up the maker of the tile online and read their technical specs and installation instructions. If the tile is rectified, you will install with narrower grout lines than if it is not. The grout color should match the main field color of the tile. Use spacers. Usually it works to back butter with a smaller toothed trowel than you use on the floor itself. Good luck!

Yes i agree with sstarr
actually its depend upon the surface and product you use
my advice to you is to log on to www.eskandaristone.com for free consultation and more variety of tile etc