A normal-shaped distribution has a μ = 80 and a standard deviation of σ =15.
a. Sketch the distribution of sample means for samples of n = 25 from this population
b. What are the z-score values that form the boundaries for the middle 95% of the distribution of sample means?
c. 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?