For some one-electron system with $l=0$ and $m=0$, the functions $N_0 e^{-\sigma}$ and $N_1(2-\sigma)e^{-\sigma}$ refer respectively to the ground $(E_0)$ and first excited $(E_1)$ energy levels. If a variational wave function $N_2(3-\sigma)e^{-\sigma}$ yields an average energy $\bar{E}$, it will satisfy