Albuterol, a bronchodilator of the beta-2 adrenergic drug type, can be administered by nebulizer or inhaler. A nebulizer treatment for an adult patient consists of 2.5 mg of albuterol in the form of albuterol sulfate solution. This is administered from 5 to 15 minutes, three to four times a day. If the concentration of the solution is 1.25 mg/3 ml, how many milliliters are required for four administrations?