Within thirty (30) days after his or her appointment, or such longer time as may be allowed by the probate court, a guardian shall return to the probate court, under oath, an inventory and appraisement of all the real and personal estate of his or her ward, to be made by a suitable, disinterested person or persons appointed by the court, which shall fix the number of appraisers at one or three (3) in its discretion. The appraisers shall be sworn to the faithful discharge of their trust.