A Researcher Was Interested in the Effects of Arousal and Personality

A researcher was interested in the effects of arousal and personality on individuals' GRE test performance.The personality variable he examined was individuals' level of introversion-extraversion.Based on questionnaire responses,each participant was classified as an "extravert" or an "introvert." The researcher manipulated arousal level by giving caffeine to participants prior to administering a practice GRE test.Participants were randomly assigned to a high-caffeine condition,a medium-caffeine condition,or the no-caffeine condition.All participants then completed a version of the quantitative portion of the GRE.
Suppose the researcher observed the following means for each group: The researcher claims that the Arousal and Group variables in this experiment are not relevant independent variables.State whether you agree or disagree with this statement,and explain your reasoning.