In a football game, a receiver is standing still, having just caught a pass. Before he can move, a tackler, running at a velocity of +3.87 m/s, grabs him. The tackler holds onto the receiver, and the two move off together with a velocity of +1.83 m/s. The mass of the tackler is 95.9 kg. Assuming that momentum is conserved, find the mass of the receiver.