8. What is the appropriate null hypothesis for an ANOVA analysis of the situation below? An industrial psychologist is investigating the effects of work environment on employee's attitude. A group of 20 recently hired trainees were randomly assigned to one of four different rooms (5 trainees per room). Each room has a different wall color: green, blue, gray. and red. At the end of the training period, the attitude of each trainee was measured. The psychologist wants to know if room color has an effect on attitude. Choice 1:H, : , =*=Ng=x4 (x's - room colors) Choice 2: H, : 14 = 1 = 16 = HA =Us (mu's - people's attitudes) Choice 3: Ho : /gran = /glu = gray = /red (mu's - mean room attitudes) Choice 4: Ho : Pgran = Palus = Pge = Pred (p's - proportion with good attitude) C a. Choice 1 b. Choice 4 c. Choice 2 d. Choice 3