STAT332 Study Guide - Final Guide: Document Camera, Null Hypothesis, Blackboard
Document Summary
1. (a) the treatments are vertical arrangements of three letters a, b, c corresponding to the three brands. There are 3!=6 such arrangements. (b) divide the 24 stores into six groups of four at random. Then assign a di erent treatment to each group. Note that there are four units (replication) within each group. (c) divide the stores into four blocks of six based on some explanatory variate such as previous weekly average sales. Within each block this explanatory variate should be as constant as possible but it can vary between the blocks. Then, within each of the four blocks, assign the six treatments at random to the six stores. Note that each treatment is applied to four stores, one per block (replication). (d) blocking is useful to avoid confounding and to increase the precision of the treatment compar- isons.
