Which of the following statement(s} is/ are correct? I. A test for the difference between two proportions can be performed using the chi-square test. II. When testing for independence in a contingency table with 3 rows and 4 columns. there are T degrees of freedom. III. C hi-square goodness-of-t test is always a one-tailed test. TV. If we use the Chi-square test of independence. we must assume that there are at least 5 observed frequencies in each cell of the contingency table