I have a hotpoint drier with a 3 prong cable and plug, male. The center is aparently ground. I have a 4 hole (female) receptacle. I disconnected the 3 wires from the drier's 3 screws, which connect to the 3 prongs of the plug. I will exchange the 3 prong plug and cable for 4 prong plug and cable. How do I connect the 4 prong cable to the 3 termials on the drier?