When an estate is in a condition to be closed before filing his final settlement and petition for distribution, the personal representative shall give, or cause to be given, at least twenty-nine days’ notice by publication in the manner provided by section 472.100 stating (1) that he will file final settlement and petition for distribution on a date certain or as continued by the court, and (2) that objections to the final settlement or petition for distribution shall be in writing and filed within twenty days from the date the final settlement is filed. The notice shall be published once a week for four consecutive weeks, the last publication to be at least seven days prior to the date specified therein for filing of the settlement. At least fifteen days before the date specified in the published notice the personal representative shall give, or cause to be given, the same notice by ordinary mail to each heir and devisee then interested in the estate whose name and address is disclosed by the court records, and who has not, in writing, waived such notice. Prior to the approval of the final settlement, proof of service as provided in section 472.110 and any written waivers shall be filed.