Sum of the column using Awk

[Rvir]

Iam doing a awk on a column in file to find its sum. I have a process which generates a file and then this script runs and determines the sum.The source data which is used to generate the file is same all the time .Everytime i re run this process with same data i get different sum for each run.Please find my script below.
Begin
s+=$2
End
{
printf (" 7.2f\n" s )
}
The data in this column is decimal. The number records more than 700000 so its tough for me to find unprintable characters .Is there any way i can check unprintable characters and iam trying to think what could be other reasons. i did difference of last run file and prior file and found no difference in data in the column

 

[PHV]

What about this program instead ?

{s+=$2}
END{printf "%7.2f\n",s}

Hope This Helps, PH.
FAQ219-2884
FAQ181-2886

 

[Rvir]

My mistake , this the code i use for calculating sum .

BEGIN {FS = "\t"}
{
s1 += $2;
}

END
{printf "COST AMT $%7.2f\n",s1 ;
}