In any county now or hereafter having a population of not less than 5,000 inhabitants, as determined by the last federal decennial census or by any federal decennial census hereafter taken, where there are areas outside of incorporated cities for which adequate fire protection is not provided, the board of supervisors by a 2/3 vote of its membership of any such county shall have authority (1) to purchase fire extinguishing apparatus and equipment; (2) to provide for the housing, maintenance, care and operation thereof for any such areas within such county; or (3) to contract for such fire protection with the legislative body of any township, city or village located within such county; (4) to carry on an educational campaign for fire prevention and fire protection in such areas, and (5) to make such appropriation from the general fund of such county as such board of supervisors shall deem necessary for these purposes: Provided, That the county shall furnish fire protection to only such townships as have entered into a contract with the county to reimburse the county for such percentum, which in any case shall not be less than 50 percentum, of the cost of furnishing such fire protection as shall be determined by the board of supervisors.