posted by sara .
You are given the following information obtained from a random sample of 4 observations.
25 47 32 56
At a .05 level of significance, determine whether or not the mean of the population from which this sample was taken is significantly different from 48. (Assume the population is normally distributed.)
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 the Z score.