The physical fitness of a patient is often measured by the patient's maximum oxygen uptake (recorded in milliliters per kilogram, ml/kg). The mean maximum oxygen uptake for cardiac patients who regularly participate in sports or exercise programs was found to be25.5,with a standard deviation of6.7.Assume that this distribution is approximately normal. Find the following.(Note: Give answers as decimal proportions, not percentages.)

(a) What is the probability that a cardiac patient who regularly participates in sports has a maximum oxygen uptake of at least18.9 ml/kg?

(b) What is the probability that a cardiac patient who regularly exercises has a maximum oxygen uptake of8.08 ml/kg or lower?