I'm stuck on question C and if I can also get better understanding on the other 3 problems

Suppose the age that children learn to walk is normally distributed with mean 13 months and standard deviation 1.4 month. 6 randomly selected people were asked what age they learned to walk. Round all answers to 4 decimal places where possible. a. What is the distribution of X? X - N( 13 1.4 b. What is the distribution of a? x - N( 13 0.5715 c. What is the probability that one randomly selected person learned to walk when the person was between 11.5 and 14 months old? d. For the 6 people, find the probability that the average age that they learned to walk is between 11.5 and 14 months old. e. For part d), is the assumption that the distribution is normal necessary? O NoO Yes f. Find the IQR for the average first time walking age for groups of 6 people. Q1 = months Q3 = months IQR: months