  We present a projection study for the first moments of the inclusive spin
structure function for the proton and neutron from simulated doubly-polarized
e+p and e+3He collision data expected from the Electron-Ion collider. For
detection and extraction of the neutron spin asymmetries from e+3He collisions,
we used the double-tagging method which significantly reduces the uncertainty
over the traditional inclusive method. Using the Bjorken sum rule, the
projected results allow us to determine that the QCD coupling at the Z-pole
alpha_s can be measured with a relative precision of 1.3%. This underscores the
significance of the EIC for achieving precision determinations of alpha_s.
