What is secondary data? 3. You are testing the impact of heart medication on children aged 12 and below. You start with a set of 50 boys and 50 girls. You divide them into two groups based on gender. You then use a random selection method to select a sample of 20 from each group. What type of sampling method is this? 4. Take a look at this box plot and determine the five-number summary for this data set