In Canada the ages of smart phone users approximately follow a normal distribution with approximate mean and standard deviation of 43.6 years and 11. 9 years , respectively, use Empirical Rule to answer : a) determine the probability that a random smart phone user in the age is between 19.8 and 67.4 years old bad b) Determine the probability that a randomly selected smart phone user s at most 79.3 years old. () determine the probability that a randomly selected smart phone user IS at least 31. 7 years old a) determine 16% of users Is above what age