According to the IRS, the average refund in the 2011 tax year was $3,109. Assuming that the standard deviation for these refunds was $874, what is the standard error of the sample mean for a random sample of 50 tax returns?
A) $74.66
B) $100.56
C) $123.60
D) $152.25

Question

Quizplus · Accepted Answer

The formula for the standard error of the sample mean is:
SE = σ/√n
where σ is the standard deviation of the population and n is the sample size.
In this case, σ = $874 and n = 50. Thus, 
SE = 874/√50 = $123.60
Therefore, the correct answer is C.

According to the IRS, the Average Refund in the 2011