River City Is Seeking to Compare the Effects of Two

Essay

River City is seeking to compare the effects of two mosquito sprays, A and B, to beused in the insect control plan for their park system. Consider the following twoplans for a statistical study:• In Plan #1, a simple random sample of plots of park land would be taken from thepopulation of River City parks. Either treatments A or B would be randomlyassigned to each of the plots.• In Plan #2, simple random samples of plots of park land would be taken fromeach of four geographic areas in River City. (River City has 4 geographic areas oftown, the NE, NW, SE, and SW quadrants.) Either treatments A or B would berandomly assigned to each of the plots within each geographic area.
a) Consider study plan #1:i) Would it be appropriate to infer a cause-and-effect relationship if the results ofthe two treatments differ?
Why or why not?
ii) Could the results be generalized to all areas of the park land?
Why or whynot?
b) Consider study plan #2:i) Would it be appropriate to infer a cause-and-effect relationship if the results ofthe two treatments differ?
Why or why not?
ii) Could the results be generalized to all areas of the park land?
Why or whynot?