Kenny pulls with a force of 850 N. Justin pushes with a force of 650 N. The crate weighs 1250 N and sits on a ramp that is 40 degrees from the horizontal. Tyler is pushing at an angle of 35 degrees with respect to the crate. There is an angle of 50 degrees between Tanner's rope and the crate. What is the highest that mu (μ) can be in order for them to get the crate up the ramp?