Question

Assume standard deviation of all invoices is $200. Sample 100 invoices. What is the standard deviation of xbar

Answer 1

20

Explanation:

Standard deviation of the mean is expressed as:

SM = s/√n

s is the standard deviation of all invoices

n is the sample size of the invoiced

Given

s = $200

n = 100

Required

Standard deviation of the mean

Substitute the given parameters into the given equation

SM = 200/√100

SM = 200/10

SM = 20

Hence the standard deviation of xbar is 20