The health care provider has prescribed an oxytocin infusion to begin at 0.5 mu/min and then increase by 1 mu/min every 30 minutes until regular contractions begin. The maximum safe dose is 20 mu/min. the pharmacy provides a 500 ml bag of 5% dextrose in water with 15 units oxytocin. Calculate the iv rate (in ml/h) for the beginning infusion.