View Compilation Error

0_0_34106385_16845.cpp: In function 'int main()':
0_0_34106385_16845.cpp:6:9: error: 'sum' was not declared in this scope
         sum = 0.0;
         ^
0_0_34106385_16845.cpp:18:9: error: 'ave' was not declared in this scope
         ave = sum / (n - 2);
         ^