Ciprofloxacin is a quinolone antibiotic used in the treatment of urinary tract infections. After administration of a single iv dose of 10 mg/kg ciprofloxacin the AUC calculated using the trapezoidal rule was 28 mg-hr/L. If the AUC calculated after administration of a single oral dose of 5 mg/kg ciprofloxacin to the same individual was 8.4 mg-hr/L, calculate the absolute bioavailability of this oral formulation.