Continuing with the previous question, a survey asks a group of students if they buy CDs or not. It also asks if the students own a smartphone or not. These values are recorded in the contingency table below. What is the test statistic, 20, for this test for homogeneity? Round the final answer to one decimal place. CDs No CDs Row Total Smartphone 7 21 28 No Smartphone 13 10 23 Column Total 20 31 51 Provide your answer below: $$