Cpp Task 16 problem

Hi, i have some a problem with the task # 16 (Average of an Array). My function that calculates avg:

int avg(std::vector<int>& v){
    v.pop_back(); // Removes 0
    return std::accumulate(v.begin(),v.end(),0) / v.size();
}

Input data:

11
312 142 146 117 192 292 55 329 0
483 5119 5623 3236 73 15013 11739 14547 11459 6360 15967 14875 0
387 240 392 222 474 48 347 274 0
12482 12168 8647 14215 6286 3313 13675 6768 8431 0
2126 386 1340 1667 3251 2930 0
172 2634 1867 2091 1670 3639 1787 2049 2311 0
8575 12004 10025 837 9834 16311 4149 7125 6695 12580 10039 315 4699 11581 5673 0
126 154 414 212 1471 1347 1257 258 1118 102 1282 225 0
1297 1543 220 1402 724 0
12912 8375 11553 6566 8689 16252 0
11233 9959 15367 12464 13263 673 0

My answer:

198 8707 298 9553 1950 2024 8029 663 1037 10724 10493

Expected answer:

198 8708 298 9554 1950 2024 8029 664 1037 10725 10493

As you can see, some values has a different of 1 unit, i don't know why.. Maybe some conversion due to the division by the array size?

Thanks, now it works:

int avg(std::vector<int>& v){
    v.pop_back(); // Removes 0
    return std::round(std::accumulate(v.begin(),v.end(),0.0f) / v.size());
}