Voters in three counties approved a property tax that is expected to raise $23 million a year for the Detroit Institute of Arts, which has an inadequate endowment and receives no financial support from either the city or the state. The museum’s collection ranges from Egyptian artifacts to modern and contemporary art, and its great hall houses Diego Rivera’s monumental mural scheme celebrating the auto industry and its workers. There had been considerable fear that if the tax were not supported the museum would face an uncertain future, with closure a possibility.