Chu (1970) studied the effect of the insecticide chlordane on the nervous systems of American cockroaches. The coxal muscles from one mesoand one metathoracic leg on opposite sides were surgically extracted from each of six roaches. The roaches were then treated with 50 micrograms of α-chlordane, and coxal muscles from the two remaining meso- and metathoracic legs were removed about two hours after treatment. The Na+-K+ATPase activity was measured in each muscle, and the percentage changes for the six roaches are given here:
Test the null hypothesis that the chlordane treatment has not affected the Na+-K+ATPas activity. What experimental technique (not mentioned in the description above) must have been used to justify a randomization test?