1412
534 + 223 = 757
2 plus 876 is 878.
462,019,915
84.
Use a Calculator.
67 + 467 = 534
It is (677 + 878)/2 = 777.5
878 = DCCCLXXVIII in Roman numerals
Try 876 plus one or 878 minus one. There are a few other combinations that will fit.
0.0103
The average of 878 and 722 is 800.
33.7692