In the orbital hybridization theory, the $s$ and the $p$ orbitals are said to combine to form hybrid orbitals which are degenerate in energy.
How does the linear combination of the $s$ and $p$ orbitals result in (in carbon, for example) four degenerate orbitals?
Why is this configuration is more favorable than separate $s$ and $p$ orbitals?
Is the energy of the four hybrid orbitals between the energy of the non-hybrid $s$ and $p$ orbitals?
How would I go about verifying that this orbital configuration is more favorable?