The 5th number is counted in both the first 5 and last 5 sums.<br><br>
• Sum of all 9 numbers = 9 × 40 = 360<br>
• Sum of first 5 numbers = 5 × 38 = 190<br>
• Sum of last 5 numbers = 5 × 44 = 220<br>
• Sum of first 5 + last 5 = 190 + 220 = 410<br>
• This counts the 5th number twice.<br>
• 5th number = 410 − 360 = 50<br><br>
Final Answer: 50