The Economic Policy Institute periodically issues reports on wages of entry-level workers. The institute reported that entry-level wages for male college graduates were $21.68 per hour and for female college graduates were $18.80 per hour in 2011 (Economic Policy Institute website, March 30, 2012). Assume the standard deviation for male graduates is $2.30, and for female graduates it is $2.05.

Question

a. What is the probability that a sample of 50 male graduates will provide a sample mean within $.50 of the population mean, $21.68?

b. What is the probability that a sample of 50 female graduates will provide a sample mean within $.50 of the population mean, $18.80?

c. In which of the preceding two cases, part (a) or part (b), do we have a higher probability of obtaining a sample estimate within $.50 of the population mean?

Do we have a higher probability of obtaining a sample estimate within $.50 of the population mean?

d. What is the probability that a sample of 120 female graduates will provide a sample mean more than $.30 below the population mean?

Answer 1

Z = (score-mean)/SEm

SEm = SD/√n

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions/probabilities related to your Z scores.

Answer 2

I need in answers of the questions pls

Answer 3

B.2.05/square root of (50)=.2899
.5/.2899=1.724732667
Under the z score table lookup +/- 1.72
=.9573-.0427
=.9146