Question

Assume that a set of raw scores are normally distributed with mean= 120 and the standard deviation=40. Describe the sampling distribution of the mean for each of the following sample sizes.

a. N=25
b. N=100
c. N=400

Answer 1

sampling dist. of the mean has the same mean as the underlying data (120), but the std. dev.
is s/sqrt(N). So, for example, for N=25, std dev is 40/sqrt(25)=8.00.
you will see that as sample size increases, the std error decreases (since the denominator
sqrt(N) increases).

Answer 2

Thank you!!!

Answer 3

np!!!!!!!!!!!

Answer 4

Where does the 120 come into play though, sorry just trying to fully understand it