A psychologist who is investigating the effects of different levels of sweetness on fluid consumption would like to use the...

A psychologist who is investigating the effects of different levels of sweetness on fluid consumption would like to use the same participants in each condition. She is worried, however, that the order of the conditions may influence participants' responses and decides to use the complete counterbalancing design. In earlier studies, she used 120 participants. In the current study, she would like to use 7 conditions and finds that the number of participants needed increases: