Total age = number of members × average age.<br><br>
• Total age of 4 members = 4 × 28 = 112 years<br>
• Total age of other 3 members = 112 − 2 = 110 years<br>
• Average of other 3 = 110 ÷ 3 = 36 \(\frac{2}{3}\) years<br><br>
Final Answer: 36 \(\frac{2}{3}\) years old