The lengths of adult males' hands are normally distributed with mean 189 mm and standard deviation is 7.4 mm. Suppose that 15 individuals are randomly chosen. Round all answers to 4 where possible.
a. What is the distribution of ¯x? x¯ ~ N( , )
b. For the group of 15, find the probability that the average hand length is less than 191.
c. Find the first quartile for the average adult male hand length for this sample size.
d. For part b), is the assumption that the distribution is normal necessary? No Yes