1. **State the problem:** Represent the number 349007.9 in standard form. 2. **Formula and explanation:** Standard form (also called scientific notation) expresses a number as $a \times 10^n$ where $1 \leq a < 10$ and $n$ is an integer. 3. **Step-by-step conversion:** - Move the decimal point in 349007.9 so that only one non-zero digit remains to the left: 3.490079 - Count how many places the decimal point moved: it moved 5 places to the left. 4. **Write in standard form:** $$349007.9 = 3.490079 \times 10^5$$ 5. **Explanation:** This means 3.490079 multiplied by 10 raised to the power of 5 equals 349007.9. **Final answer:** $$3.490079 \times 10^5$$