1. **State the problem:** We need to find the mean (average) age of the youngest leaders given the ages: 33, 37, 37, 39, 39, 41, 43, 43, 44, 45. 2. **Formula for mean:** The mean is calculated by summing all the values and dividing by the number of values. $$\text{Mean} = \frac{\text{Sum of all ages}}{\text{Number of ages}}$$ 3. **Calculate the sum:** $$33 + 37 + 37 + 39 + 39 + 41 + 43 + 43 + 44 + 45 = 401$$ 4. **Count the number of ages:** There are 10 ages in total. 5. **Calculate the mean:** $$\text{Mean} = \frac{401}{10} = 40.1$$ 6. **Interpretation:** The average age of the youngest leaders at the time of assuming office is 40.1 years.