Bob and Mark are competing in a 1km swimming race. Assume that Bob's average time to finish this type of race is 28.4 minutes with standard deviation of 2.1 minutes, and that Mark's average time is 30.8 with a standard deviation of 1.9 minutes. Assuming their race times are independent, what is the probability that Mark will achieve a lower time and win the race?Answer as a probability (between 0 and to four decimal places.