Explanation:

- Let's assume the population two years ago was $P$.

- First year: Population increased by 30%:

- New population = $P+0.3P=1.3P$.

- Second year: Population decreased by 15%:

- New population = $1.3P\times 0.85=1.105P$.

- Current population is given as 11,050.

- We set up the equation: $1.105P=11050$.

- Solve for $P$ by dividing both sides by 1.105:

- $P=\frac{11050}{1.105}\approx 10,000$.

- Option 1: 10,000 - This is the correct answer.

- Option 2: 99,500 - Incorrect if solving the equation.

- Option 3: 99,000 - Doesn't match the calculation result.

- Option 4: 10,050 - Close but not precise.