The comparison-wise error rate is the probability of a Type I error in any comparison. There is no evidence of a difference between the average tar content of the Hacker and Killer brands. The Hacker brand appears to have lower mean tar content than the Choker brand. The analyst now wishes to perform a new experiment to distinguish among three different brands. She believes that the value of 4 is a good estimate of the population standard deviation.
Every block is randomized separately from every other block.
Every treatment must appear at least once in every block. Block should contain experimental units that are as different as possible from each other. The following questions refer to the following situation. The pest, which is particularly troublesome in warm climates, can be treated by the application of nematocides. However, because of the size of the worms, it is very difficult to count them directly.