What is the magnitude of RMP in a typical skeletal muscle cell?

The resting membrane potential in skeletal muscle cells is mostly due to the K+ concentration ratio across the sarcolemma membrane. This is because there is a larger number of K+ channels as compared to Na+ channels, and all cell membranes are more permeable to K+ than to Na+. 

The RMP in a typical skeletal muscle cell is -90 mV.