You have ALREADY done this calculation:
If the skier starts from rest at the top of the ramp, and slides without friction, how fast will he be moving when he leaves the ramp at the bottom?
However, in real life, skiers don't reach the bottom of the ramp with the theoretical speed. Instead, the actual speeds are closer to about v = 26 m/s.
Let's pretend that the only reason for this discrepancy is friction between the skis and the icy ramp. If that's the case, what is the coefficient of kinetic friction between the skis and the ice?
Fine. But ... is this correct? Compare your value to the coefficients of static friction we measured earlier between a metal track and a block covered with fabric.