Answer:
10 lb of force are needed to lift the rock if the distance from the fulcrum is 6 feet.
Explanation:
From the given graph it is clear the curve passing through the point (1.5,40), (2,30), (2.5,24), (3,20) and (4,15).
These points satisfy by the equation
![y=(60)/(x)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/fz7zy6set103giu4rlvnk8rpp20unn2mqz.png)
where, x is the distance in feet from the fulcrum and y is needed force in pounds.
Put x=6 in this equation,
![y=(60)/(6)=10](https://img.qammunity.org/2020/formulas/mathematics/middle-school/fku7zhfm56e32fwsrrb2xkpqmnru0v2nwy.png)
Therefore, 10 lb of force are needed to lift the rock if the distance from the fulcrum is 6 feet.