Data
Weight of the baby = 15 lb
Dosage = 80mg/2.5 ml
Amount given = 3.0 ml
Use a rule of three to solve this problem
80 mg --------------------- 2.5 ml
x -------------------- 3.0 ml
mg that the baby received = (3 x 80) / 2.5
= 240 / 2.5
= 96
Substract = 96 - 80
= 16
Excess of dosage = 16 mg