Suppose that, on average, electricians earn approximately µ = $54,000 per year in the United States. Assume that the distribution for electricians' yearly earnings is normally distributed and that the standard deviation is σ = $12,000. Given a sample of four electricians, what is the standard deviation for the sampling distribution of the sample mean?
A) 6,000
B) 12,000
C) 36,000
D) 54,000

Question

Quizplus · Accepted Answer

The standard deviation of the sampling distribution of the sample mean (σx̄) is equal to the population standard deviation (σ) divided by the square root of the sample size (n). Here, σ = $12,000 and n = 4, so σx̄ = $12,000 / √4 = $12,000 / 2 = $6,000.

Suppose That, on Average, Electricians Earn Approximately µ = $54,000