posted by Anonymous .
If μ =10 and σ =4 for a distribution of sample mean, with n=16 for each mean, how far
above the population mean (in %) is a sample mean score of 12
Z = (mean1 - mean2)/standard error (SE) of difference between means
SEdiff = √(SEmean1^2 + SEmean2^2)
SEm = SD/√(n-1)
If only one SD is provided, you can use just that to determine SEdiff.
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to that Z score.