The census figures show that the average income for a family in a rural region is approximately $34,860 per year. A random sample has a mean income of $33,566 per year, with a standard deviation of $1,245. At a sig. level of .0.01 is there enough evidence to reject the claim?

Question

The census figures show that the average income for a family in a rural region is approximately $34,860 per year. A random sample has a mean income of $33,566 per year, with a standard deviation of $1,245. At a sig. level of .0.01 is there enough evidence to reject the claim?

Answer 1

Z = (score-mean)/SEm

SEm = SD/√n (How large was the sample?)

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability of the Z score. Is it <.01?