21.A researcher must calculate the population mean to calculate the confidence intervals.
22.The confidence interval increases as the sample size, n, increases.
23.Three factors are required to specify sample size: (1) the variance of the population; (2) the population mean; and (3) the confidence level.
24.The variance, or heterogeneity, of the population refers to the standard deviation of the population.
25.In most cases, the size of the population does not have a major effect on the sample size.