SOLUTION STEPS (Set 7):
  1. Find the step: 2.09 - 2.07 = 0.02. Each term adds 0.02.
  2. Next terms: 2.09 + 0.02 = 2.11, then 2.11 + 0.02 = 2.13.
  3. Check: 2.13 + 0.02 = 2.15. Matches. The missing numbers are 2.11 and 2.13.