The heights of a group of students are modelled by a normal distribution with mean 165 cm and standard deviation 6.8 cm. The weights of this group of students are modelled by a normal distribution with mean 55 kg and standard deviation 8.2 kg. Find the probability that a randomly chosen student: i. taller than 170 cm ii. weight is at most 62 kg iii. height is taller than 168 cm but less than 175 cm