The average price of a college math textbook is $166 and the standard deviation is $21. Suppose that 13 textbooks are randomly chosen. Round all answers to 4 decimal places where possible. What is the...

The average price of a college math textbook is $166 and the standard deviation is $21. Suppose that 13 textbooks are randomly chosen. Round all answers to 4 decimal places where possible.

1. What is the distribution of ¯xx¯? ¯xx¯ ~ N(,)


2. For the group of 13, find the probability that the average price is between $169 and $174.


3. Find the third quartile for the average textbook price for this sample size. $ (round to the nearest cent)


4. For part b), is the assumption that the distribution is normal necessary? YesNo