Total number of 10th graders x Percentage of 10th graders who used anabolic steroids in the past month = Number of 10th graders who used anabolic steroids in the past month
12,000 students x (0.8)/(100) = 96 students used anabolic steroids in the past month

Total number of 10th graders – Number of 10th graders who used anabolic steroids in the past month = Number of 10th graders who did not use anabolic steroids in the past month
12,000 students – 96 students = 11,904 student did not use anabolic steroids in the past month

D. 11,904

Total number of 8th graders x Percentage of 8th graders who used anabolic steroids = Number of 8th graders who used anabolic steroids
20,000 students x (1.9)/(100) = 380 students used anabolic steroids

Total number of 8th graders – Number of 8th graders who used anabolic steroids = Number of 8th graders who did not use anabolic steroids
20,000 students – 380 students = 19,620 students never used anabolic steroids

D. 19,620

According to the table about the 2004 study with regards the abuse of anabolic steroids among the 8th, 10th, and 12th grade students from both private and public schools, the percentage of the 12th grade students who abuse anabolic steroids are higher compared to the percentage of the 8th and 10th graders.
And the logical explanation for this is that senior high school students are becoming conscious with regards their body appearances and are inclined with several extracurricular activities, especially with the preparation for their new beginnings in college. Lastly, some students are athletes which consume anabolic steroids in order to increase their body mass and muscles.