One fourth of the opposite of the difference of five and a number is less than twenty

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.

Find the area of the triangle shown 3 by 6

Is the power produced directly proportional to the wind speed, give reasons for your answer?