I'm in the process of remodeling my kitchen.
My old electric range was hard wired to a wire coming out of a hole in the wall.
There are 3 wires, a white, a black and a bare copper.
Lowe's said they will not hard wire my new range, that I need a receptacle to plug in the range.
They said current code requires a 4 prong plug.
I am OK with installing this myself, but do not know how to wire a four prong receptacle to only 3 wires.
I hate to have to rewire the feed from the box to upgrade.
I also would rather not hire an electrician for such a simple task.
How do I do this?

I forgot to mention this is for 240 volt.

The bare wire goes to ground, the white to hot, and black to hot, the other leg.