The healthcare provider prescribes ampicillin 140 mg intravenously (IV) every 8 hours for a child with meningitis. The vial is labeled, "Ampicillin 250 mg for reconstitution with 8.3 ml, sterile normal saline for injection to yield a total solution concentration of 30 mg/mL." How many mL should the nurse administer? (Enter the numeric value only. If rounding is required, round to the nearest tenth.)