We first calculate the work effectively done by the force when it compressed the steel cylinder. This is solved by multiplying the distance that the cylinder was compressed by and its causing force.
0.010 m * 13,000 N = 130 N-m
Then, we solve for the work done by the 1,500 N force:
0.10 m * 1,500 N = 150 N-m
We then take the ratio of the efficient:experimental
130 N-m / 150 N-m = 0.87 = 87%