# l. H0: p1=p2=p3, where p1 is the proportion of the sample of sophomores that responded yes, p2 is the proportion of the sample of juniors that responded yes, and p3 is the proportion of the sample of seniors that responded yes. ll. H0: There is an association between grade level and whether or not a student regularly recycles plastic bottles. lll. H0: There is no difference in the distribution of regular recyclers across the three grade levels. A) II only B) III only C) I and II only D) I and III only E) I, II, and III

l. H0: p1=p2=p3, where p1 is the proportion of the sample of sophomores that responded yes, p2 is the proportion of the sample of juniors that responded yes, and p3 is the proportion of the sample of seniors that responded yes. ll. H0: There is an association between grade level and whether or not a student regularly recycles plastic bottles. lll. H0: There is no difference in the distribution of regular recyclers across the three grade levels.

A) II only

B) III only

C) I and II only

D) I and III only

E) I, II, and III

## Answer

Answer: B) III only

Explanation: The null hypothesis for a chi-square test for homogeneity or independence should state that there is no difference or association between variables. The correct null hypothesis here is “There is no difference in the distribution of regular recyclers across the three grade levels.”