A nurse is preparing to administer diphenhydramine 25 mg/kg IM to a child who weighs 66lb. Available is diphenhydramine injection 50 mg/mL. How many mL should the nurse administer? (Round the answer to the nearest tenth. Use a leading zero if it applies. Do not use a trailing zero.)

Step-by-step calculation: Convert weight to kilograms: 66 lb ÷ 2.2 = 30 kg Calculate total dose in mg: 25mg/kg × 30 kg = 750 mg Calculate volume to administer using concentration 50 mg/mL: 750 mg÷50 mg/mL=15 mL. Round to nearest tenth → 15.0 → per instructions omit trailing zero → 15 mL. Answer: 15 mL.