6. A study is conducted in a defined population in which 30% are single and 70% are married. There are 100 individuals needed as the sample. The researcher randomly choses 30 single and 70 married individuals. 7. A researcher is conducting a study about the effectiveness of using algebra tiles in teaching factoring among grade 8 students. He grouped the students homogeneously according to their mathematical ability. The table below shows the groups formed with their corresponding sizes. Math ability Group size Beginning 18 Developing 50 Approaching Proficiency 130 Proficient 17 Advanced 15 TOTAL 230