Tidewater plans to sell 89,000 units of product no. 794 in May, and each of these units requires three units of raw material. Pertinent data follow. Product No.794 Raw Material Actual May 1 inventory 13,000 units 26,000 units Desired May 31 inventory 16,000 units 21,000 units On the basis of the information presented, how many units of raw material should Tidewater purchase for use in May production?