Can the mass of the star and speed be used to conclude the attraction of the black hole?
As you formulate it, your question doesn't make much sense.
Assuming that you are asking if, based upon an estimate of the mass of the visible star and its observed orbital period (and hence: orbital speed), can one calculate the mass of the black hole, then: Yes.
Assuming that the visible star is much less massive than the visible star (say, less than 10% the mass of the black hole), one can even neglect the mass of the visible star.
It is a 1st-year college physics level calculation.
Regards,