Four types of advertising displays were set up in 12retail outlets, with three outlets randomly assigned to each of the displays, for the purpose of studying the point-of-sale impact of the displays....

Four types of advertising displays were set up in 12retail outlets, with three outlets randomly assigned to each of the displays, for the purpose of studying the point-of-sale impact of the displays. With reference to Table 13.15, test the null hypothesis that there are no differences among the mean sales values for the four types of displays, using the 5 percent level of significance.

Table 13.15

Table 13.15 Product Sales According to Advertising Display Used