Please help !! Don’t understand:((

Which expression is equivalent to? assume x > 0 and y > 0.

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 60 with a standard deviation of 7.2. assume that the distribution is approximately normal.

Name the most appropriate metric unit for each measurement