Question

A sample of n = 4 scores is selected from a population with μ = 50 and σ = 12. If the sample mean is M = 56, what is the z-score for this sample mean?​

Answer 1

For this answer, we use this formula:

Z = ( X - U ) / ( S / √n )

Where:

X = sample mean

U = population mean

S = population standard deviation

n = number of samples

Now, we can put the amounts into the formula:

Z = ( 56 - 50) / ( 12 / √4 )

Z = 1

So, z is 1, which means that the data point is 1 standard deviation from the mean.