Well this is for a physics project and a lot of it depends on guessing. We found friction to be 833 N, mass to be 85 kg, acceleration to be -2.14 m/s^2 because the cartoon characters are decelerating as they hit the wall. Will all of this μ(ma)= Friction, we found μ to be 4.58. We are just wondering if 4.58 would be too big for μ.
4.58 would be large but there's nothing in the laws of physics (as far as I know) that limits the coefficient of friction. I know at least that it can be greater than 1, so 4.58 isn't completely crazy.
Between clothing and a rock though, it would certainly be abnormal (but perhaps not impossible)