The diagram shows the outstretched arm of a gymnast who is performing an iron cross maneuver in the rings competition.

The diagram shows the outstretched arm of a gymnast who is performing an iron cross maneuver in the rings competition. The three labeled forces are the force in the latissimus Doris muscles with magnitude F, the weight of the arm with magnitude W=82.4N, and the tension in the rope with magnitude T=369N. The net torque due to these three forces about the shoulder joint is zero. The horizontal distances fro the shoulder joint to the point of application of the three forces are x1=7.25 cm, x2=30.7 cm, and x3=67.7 cm. If angle 1=21.7 degrees and angle 2=19.7 degrees, what is F?