G Which of the following statements are true? A. In some experiments, different samples contain different numbers of observations. However, the concepts and methods of single-factor ANOVA are most easily developed for the case of equal sample sizes. B. The population or treatment distributions in single-factor ANOVA are all assumed to be normally distributed with the same variance C. In one-way ANOVA, if either the normality assumption or the assumption of equal variances is judged implausible, a method of analysis other than the usual F test must be employed. D. The test statistic for single-factor ANOVA is F = MSTr/MSE, where MSTr is the mean square for treatments, and MSE is the mean square for error. E. All of the above statements are true.