To estimate the federal debt of Country C, which is $278,560,125,000, we will express this amount in scientific notation.
- Identify the leading digit: The leading digit is 2.
- Count how many places we move the decimal point to the left to get it after the leading digit (2).
- The original number is 278,560,125,000. Moving the decimal point 11 places to the left gives us 2.78560125.
- Round to two significant figures: This rounds to 2.8 for simplicity.
- Therefore, we put it in the scientific notation form:
- \(2.78560125 \approx 2.8\) becomes \(2.8 \times 10^{11}\).
- Although \(2.79 \times 10^{11}\) is close, \(2.8 \times 10^{11}\) would also be acceptable based on rounding conventions.
But given your options, the closest estimation of the federal debt in the requested form is:
2.79 × 10^11.