To compare the popularity rates of two different political candidates in their respective states, a random sample of 108 citizens from state a yielded 55 who were in favor of their state's candidate whereas 63 citizens out of the 143 selected from state b were in favor of their state's candidate. we wish to use a significance level of 0.05 to test whether there exists a difference between the popularity rates of these two candidates. the value of the test statistic rounded to two significant places after the decimal is: