Final answer:
The number 699,875 written in scientific notation to three significant digits is 7.00 × 10^5.
Step-by-step explanation:
Written in scientific notation, to three significant digits, the number 699,875 is 7.00 × 105. To express a number in scientific notation, you must move the decimal point so that there is only one non-zero digit to the left of the decimal point. For the number 699,875, the decimal point is moved 5 places to the left, which is why the exponent for 10 is 5. In order to have three significant figures, the number is rounded to 700, which is written as 7.00 to include the necessary significant digits.