Cygnus X-1

After many differnt typs of astronomical measurements, it is now that believed that X-1 is a black hole

a.  Find the location of this black hole relative to earth

b.  Caculate Schwarzchild radius of the Cygnus X-1 black hole

Help I haven't been able to find the mass of Cygnus X-1.  I cannot caculate the schwarzchild radius without this information.  I guess I am stumped.  Been on the net and totally confused.

Equation for Schwarzchild radius r=2GM/(c squared)
R=radius  G=Gravitational Constant M=Mass C= Speed of light