Why is the beta particle spectrum continuous?

The energy released during beta decay and is the same for all nuclei of one isotope is distributed between three particles – an electron, a neutron and a product nucleus. The share of the electron statistically in each specific case of beta decay accounts for a greater or lesser part of the total energy of beta decay. The energy of the beta particle is at its maximum if the energy of the neutrino is zero; if the neutrino energy is at its maximum, the electron energy is zero. Thus, the energy spectrum of beta particles is continuous.