Question

Suppose the age that children learn to walk is normally distributed with mean 13 months and standard deviation 1.2 month. 13 randomly selected people were asked what age they learned to walk. Round all answers to 4 decimal places where possible.

1. What is the distribution of XX? XX ~ N(,)
2. What is the distribution of ¯xx¯? ¯xx¯ ~ N(,)
3. What is the probability that one randomly selected person learned to walk when the person was between 12 and 13.5 months old?
4. For the 13 people, find the probability that the average age that they learned to walk is between 12 and 13.5 months old.
5. For part d), is the assumption that the distribution is normal necessary? YesNo
6. Find the IQR for the average first time walking age for groups of 13 people.
   Q1 =  months
   Q3 =  months
   IQR:  months

Answer 1