The physical fitness of an athlete is often measured by how much oxygen the athlete takes in (which is recorded in milliliters per kilogram, ml/kg). The mean maximum oxygen uptake for elite athletes has been found to be 63.5 with a standard deviation of 7.6. Assume that the distribution is approximately normal.

Find the probability that an elite athlete has a maximum oxygen uptake of at least 71.86 ml/kg.

Find the probability that an elite athlete has a maximum oxygen uptake of at most 46.78 ml/kg.

Find the probability that an elite athlete has a maximum oxygen uptake of 46.78 ml/kg.