In 1999, an incident of drug overdose occurred when a prescription that called for a patient to receive 0.5 grain of the powerful sedative phenobarbital each day was misread, and the patient was given 0.5 gram of the drug. Actually, three intravenous injections of 130 mg each were administered each day for 4 days. How many times as much phenobarbital was administered with respect to the prescribed amount? 1 grain = 64.79891 mg Show your calculations.