Thomas Boyce, a professor and pediatrician at the University of British Columbia, Vancouver, has studied interactions between individual differences in physiology ans difference in experience in determining health and well -being. Dr. Boyce found that some children are more sensitive to their environments. They do exceptionally well when the environment is supportive but are much more likely to have mental and physical health problems when the environment has challenges. You decide to do a similar study, conducting a factorial experiment to test the effectiveness of one environmental factor and one physiological factor on 9 physical health outcome. As the environmental factor, you choose two level of stressful life events. As the physiological factor, you choose three levels of immune reactivity. The outcome is number of respiratory 1 to in the previous 12 months, and the research participants are kindergartners You conduct a two-factor ANOVA on the data. The two-factor ANOVA involves several hypothesis tests. Winch of the following are null hypotheses that you could use this ANOVA to test?
i. There is no interaction between stressful life events and immune reactivity.
ii. The effect of stressful life events on number of respiratory illnesses is no different from the effect of immune reactivity.
iii. Immune reactivity has no effect on number of respiratory illnesses.
iv. Stressful life events have no effect on number of respiratory illnesses.