Elam Industries is interested in assessing customer response to four possible national promotional campaigns. Twenty retail stores were randomly selected for a preliminary trial. The twenty stores were randomly divided into four groups of five stores and each group was randomly assigned a different promotion. At the end of the trial period, average response rates were calculated for each of the four groups. Complete the ANOVA table below and use the information in the table to test a null hypothesis that the average response rate would be the same for the four populations represented in the trial. Use a significance level of .05. Report your conclusion and explain your reasoning.

ANOVA Source of Variation SS df MS F P-value F crit Between Groups 1180 (a) (g)* Within Groups 1720 b) (d) Total 2900 19