A population has a standard deviation of σ = 24. a. On average, how much difference should exist between the population mean and the sample mean for n = 4 scores randomly selected from the population?...

A population has a standard deviation of σ = 24.

a.  On average, how much difference should exist between the population mean and the sample mean for n = 4 scores randomly selected from the population?

b.  On average, how much difference should exist for a sample of n = 9 scores?

c.  On average, how much difference should exist for a sample of n = 16 scores?