The average of 9 observations was 9, that of the 1st of 5 being 10 and that of the last 5 being 8. What was the 5th observation? September 23, 2025 by Admin A. 9 B. 8 C. 7 D. 6 ✅ The correct answer is option A. 9. 1 to 9 = 9 * 9 = 81
