To determine the digit in the tenths place of the decimal number 725.391, follow these steps:
1. Identify the decimal point in the number. In 725.391, the decimal point is located between 725 and 391.
2. The tenths place is the first digit immediately to the right of the decimal point.
3. In the number 725.391, the first digit to the right of the decimal point is '3'.
Therefore, the digit in the tenths place of the decimal number 725.391 is 3.
