An infant weighs 12 lb 3ox. She is to receive principen 125 mg q6h. The label of principen states: usual dosage: adults and children weighing over 20kg; 250 mg to 500 mg qid in equally spaced doses. Children weighing 20kg or less; 100 mg/kg/day qid in equally spaced doses. What is the recommended dosage in mg per day for this infant? Use the weight rounded to the nearest tenth of a kg.