3. Researchers wished to investigate the effects of exposure to a certain toxicant and leucocyte increasing drugs on the phagocytic index of mice. They selected 20 mice and randomly allocated them to four groups according to whether they were exposed to the toxicant or were given leucocyte-increasing drugs. The measurement results are given in Table 10.25.

Please answer the following questions:

(a) Please state the H0 and H1.

(b) What assumptions should the data satisfy when ANOVA is performed?

(c) Use appropriate methods to analyze the data, construct an ANOVA table, and interpret the meanings represented.

(d) Can the main effect be directly interpreted in

(c) and why? If the interaction effect is statistically significant, how should the results be interpreted, and what does simple effect imply at this point?

(e) If the interaction effect is not statistically significant, how should the main effect be analyzed and interpreted?