The amount of time to complete a physical activity in a PE class is approximately normally distributed with a mean of 34.7 seconds and a standard deviation of 6.9 seconds. a) What is the probability that a randomly chosen student completes the activity in less than 29.7 seconds? b) What is the probability that a randomly chosen student completes the activity in more than 40.7 seconds? c) What proportion of students take between 31 and 40.4 seconds to complete the activity? d) 75% of all students finish the activity in less than 44.71 seconds.