it gave a hint: if your arm is horizontal and the weight points straight down, then what is the perpendicular distance from the joint to the weight?

Enter your values in the boxes, using just two significant figures. If you hold your 2.3 ft long arm out horizontally with a 12 lb weight in your hand, what is the torque about your shoulder joint caused by the weight? ft.lbs After you have an answer, convert from ft lbs to Nim to by using conversion factors between Newtons and pounds and feet and meters. N.m