Sample Mean

• the mean of X.   

•   the mean of n sample means of X

•    the mean of sample means increases.  

•  remains unchanged.    

Assume the weight of people who fly with an airline come from a population that is normally distributed with mean m and standard deviation s. What is the effect on the confidence about the average weight of a passengers the size of the plane n increases? 

• this is not related to the size of the plane

• decreases

• N(50, 2)

• N(50, 0.1)

• We cannot apply the distribution of mean of sample means because X is not known to be normally distributed.

• True

• False