Section 38N. The school committee of each city, town or regional school district shall hold a public hearing on its proposed annual budget not less than seven days after publication of a notice thereof in a newspaper having general circulation in such city, town or district. Prior to such public hearing said committee shall make available to the public at least one copy of said proposed budget for a time period of not less than forty-eight hours either at the office of the superintendent of schools or at a place so designated by said committee. At the time and place so advertised or at any time or place to which such hearing may from time to time be adjourned all interested persons shall be given an opportunity to be heard for or against the whole or any part of the proposed budget. Such hearing shall be conducted by a quorum of the school committee. For the purposes of this section a quorum shall consist of a majority of the members of said school committee.