A particular drug used in animals is eliminated metabolically by a first-order process in such a way those 2.76 hours after the initial dose of 29.7 mg/kg body weight had dropped to a level of 13.6 mg/kg bodyweight. The concentration of a drug in the body is often expressed in units of milligrams per kilogram of body weight. What must be the initial dose of this drug (in mg/kg bodyweight) in order for the level after the 2.9 hours to be 2.7 mg/kg bodyweight?