Question: IQ scores form normal distributions with σ = 15. However, the mean IQ varies from one population to another. For example, the mean IQ for registered voters is different from the mean for nonregistered voters. A researcher would like to use a sample to obtain information about the mean IQ for the population of licensed clinical psychologist in the state of California. Which sample mean should provide a more accurate representation of the population: a sample of n = 9 or a sample of n = 25? In each case, compute exactly how much error the researcher should expect between the sample mean and the population mean.