You need two of them:
1). Power = (work done) / (time to do the work)
and
2). Work = (force) x (distance)
Using the first one:
13.3 watts = (work done) / (3 seconds)
Work done = (13.3 watts) x (3 seconds)
Work done = 39.9 joules
Using the second one:
39.9 joules = (force) x (4 meters)
Force = (39.9 joules) / (4 meters)
Force = 9.975 Newtons
