Estimate the dimensionless performance characteristics and efficiency of this propeller at cruise conditions

The propeller for the Gossamer Condor human-powered aircraft has D = 12 ft and rotates at N = 107 rpm. The wing loading is 0 4 lbf/ft 2 of wing area, the drag is approximately 6 lbf at 12 mph, the total weight is 200 lbf, and the effective aspect ratio is 17. Estimate the dimensionless performance characteristics and efficiency of this propeller at cruise conditions. Assume the pilot expends 70 percent of maximum power at cruise conditions of 10.7 mph.