Can someone me with my physics homework? !

a water skier has a mass off 68kg.

calculate the resultant force acting on the water skier while accelerating.

Everybody is making something tough out of something easy.

Everybody knows the formula [ Force = (mass) x (acceleration) ].  Right ?

We're supposed to find the force on the skier when the skier is accelerating,
and it gives us the skier's mass.  So there you are !

Net force on the skier = (64 kg) x (the skier's acceleration).

It depends on the skier's acceleration, which we're not told.
More acceleration = the result of more net force.
More net force = the cause of more acceleration.

And that is absolutely everything that you can do with the information
that's given in this question.