The contingency table shows the results of a random sample of endangered and threatened species by status and vertebrate group. At α = 0.05, test the hypothesis that the variables are independent.

(a) Find the expected frequency for each cell in the contingency table,

(b) Identify the claim and state H₀ and H_a, 

(c) Determine the degrees of freedom, find the critical value, and identify the rejection region, 

(d) Find the chi-square test statistic, 

(e) Decide whether to reject or fail to reject the null hypothesis, and 

(f ) Interpret the decision in the context of the original claim.

Transcribed Image Text:

Vertebrate group Status Mammals Birds Reptiles Amphibians Fish 137 17 37 151 18 Endangered Threatened 50 23 22 12 33