You design an experiment that manipulates the following variables: method of presenting material (visual, auditory); difficulty of material (easy, difficult); and amount of material (low, moderate, high). for a completely independent groups design with 10 participants per group, how many participants will you need?

Paula maintained her normal weight during her freshman year in college. during her sophomore year, she moved into an apartment with two friends who are overweight. the three regularly enjoy high-calorie meals together, and paula has gained more than twenty pounds. she wants to lose weight, but it seems as if, whenever she plans to prepare a healthful, low-calorie meal, her roommates come home with a box of pizza or take-out burgers and fries. what type of influence are her friends having on her behavior? social undermining moral support emotional encouragement informal persuasion social undermining