Question

3. The amount of time spent by American adults playing sports per week is normally distributed with a mean of 4 hours and standard deviation of 1.25 hours. a. Find the probability that a randomly selected American adult plays sports for more than 5 hours per week. (4 marks) b. Find the probability that if four American adults are randomly selected, their average number of hours spent playing sports is more than 5 hours per week. (6 marks) c. Find the probability that if four American adults are randomly selected, all four play sports for more than 5 hours per week. (6 marks)

Fig: 1