A normal-shaped distribution has µ = 80 and ? = 15.
Sketch the distribution of sample means for samples of n = 25 scores from this population.
What are the z-score values that form the boundaries for the middle 95% of the distribution of sample means?
Compute the z-score for M = 89 for a sample of n = 25 scores. Is this sample mean in the middle 95% of the distribution?