Your research group has been hired to determine if college men and women drink different amounts of soft drinks at Illinois State University. After a careful study, your group has determined that males drink an average of 12 sodas per week with a standard deviation of 3.5 whereas female students drink an average of 9 soft drinks per week with a standard deviation of 2 sodas. The sample size of males is 200 and the sample size of females is 200. Based on this information, your group calculates the z-score to be: [____]