Answer: [tex]398.5750[/tex]
Step-by-step explanation:
It is important to remember that the fourth digit after the decimal point is in the ten-thousandth place.
Then, given the following number:
[tex]398.574986215[/tex]
You can follow these steps in order ti round it to the nearest ten-thousandth:
1. You can identify that the digit in the ten-thousandth place is:
[tex]9[/tex]
2. Identify the digit to the right of [tex]9[/tex]. This is:
[tex]8[/tex]
3. Since:
[tex]8>5[/tex]
You must round up. Increase the digit [tex]9[/tex] by 1. (Notice that [tex]9+1=10[/tex], then the digit to the left of [tex]9[/tex] increases by 1 too). Then:
[tex]398.5750[/tex]