A gymnastics class ran one mile with a mean of 11 minutes and a standard deviation of three minutes. David, a student in the class, ran one mile in eight minutes. A theater class ran one mile with a mean of nine minutes and a standard deviation of two minutes. Aubrey, a student in the class, ran 1 mile in 8.5 minutes. A physics class ran one mile with a mean of seven minutes and a standard deviation of four minutes. Art, a student in the class, ran one mile in eight minutes. Who is the fastest runner with respect to their class? Explain your answer.