Determine outcome when the energy of electron is calculated

Question

The state of an electron in 1-D cavity of length 1.0 nm in a semi conductor is described by the normalized wave function Ψ(x)= 1/2Ψ₁(x) + [1/(2i)] Ψ₂ (x) -(1/2)^1/2 Ψ₄ (x), where Ψ_n(x) is given by equation  

  Ψ_n (x) = (2/L)^1/2sin [(nπx)/L] for 0≤ x ≤ L.

Determine the outcome when the energy of the electron is calculated? Discuss the expectation value of the energy?