Michigan Compiled Laws, Chapter 700. Estates and Protected Individuals Code § 700.3701

Sec. 3701. A personal representative's duties and powers commence on appointment. A personal representative's powers relate back in time to give acts by the person appointed that are beneficial to the estate occurring before appointment the same effect as those occurring after appointment. Subject to sections 3206 to 3207,  1 before or after appointment, a person named as personal representative in a will may carry out the decedent's written instructions relating to the decedent's body, funeral, and burial arrangements. A personal representative may ratify and accept an act on behalf of the estate done by another if the act would have been proper for a personal representative.