Let X represent the full height of a certain species of tree

Let X represent the full height of a certain species of tree. Assume that X has a normal probability distribution with =38 ft and =89.6 ft.

You intend to measure a random sample of n=150 trees.

What is the mean of the distribution of sample means?
x¯=

What is the standard deviation of the distribution of sample means (i.e., the standard error in estimating the mean)?
(Report answer accurate to 4 decimal places.)
x¯=

Answer: 38

Answer: 7.3158 please tell me how to get x¯= ?

Solution

Sample Mean = x¯= = 38 [ Sample has a similar mean to population ]
x¯= = / Sqrt(150) = 89.6 / Sqrt(150) = 7.3158 [ Sample s.d = Population s.d / Sqrt(n) ]