Which if the following is/are true? Choose one or more, which ever is 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 7 degrees of freedom.

III .Chi square goodness of fit test is always a one-tailed test

IV. 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.