A sample of 322 children recently diagnosed with ADHD ages 7-10 were given ADHD medicine that the Centers for Disease Control and Prevention (CDC) was researching. Researchers wanted to see if the ADHD medicine helps with the level of focus in the morning and afternoon. One group was given the new ADHD medicine, and the other was given a placebo. What group constitutes the sample? CDC O All children ages between the ages of 7-10. 322 children O All children in the world