Answer: The another number should be -7401.
Explanation:
Since we have given that
sum of 367 and 863 is equal to sum of 8631 and another number.
Let the another number be 'x'.
According to question, it becomes,
![367+863=8631+x\\\\230=8631+x\\\\1230-8631=x\\\\-7401=x](https://img.qammunity.org/2019/formulas/mathematics/middle-school/do36vw6gl6zs9uppa1yiacjrinfkxkydnw.png)
Hence, the another number should be -7401.