a) we can read from the table the following:
Ground state: I=1/2 and mu=-0,5940mu_N. g = (-0,5940)hbar/(1/2) = -1.2528 • 10^-34 m^2 kg s^-1
245 keV: analoguesly g=-0.32 • 10^-34 m^2 kg s^-1
b) g = 2mu_B hbar/mu_N and mu_B is about 2000mu_N, which means g=4000hbar=4,218•10^-31