Answer
$23.6^{\circ}$
Work Step by Step
Step 1. Identify the given quantities: package weight $W=200$ lb, force to keep the package from sliding $F=80$ lb.
Step 2. Assume the incline angle is $\theta$, the weight force component along the incline is then given by $Wsin\theta$, as this force is balance by $F$, we have $Wsin\theta=F$
Step 3. Solve the equation: $200sin\theta=80$, we get $\theta\approx23.6^{\circ}$
