Question

Random samples of size 78 were selected from a population with mean 137 and standard deviation 4.2.

A.) What is the mean of the sample means (  x )?

B.) What is the standard deviation of the sample means (  x )?

Answer 1

Solution :

Given that ,

mean = = 137

standard deviation = = 4.2

n = 78

sample distribution of sample mean is ,

=

= 137

sampling distribution of standard deviation

=  / n = 4.2 / 78=0.4756

= 0.4756