Thanks Jean-Pierre, now I don't get any errors. But the output is wierd.

If I have the list:

1
2
1
2

This would produce:
1 2
1 2

So the output should be 1 and 2 (1+1/2 and 2+2/2 ), like so:
1
2

But instead I get

2
2

Something is wrong with the way I'm going about this problem.

echo "$data" | awk -v i=$1 '{sum+=$i} END {print sum/NR}'

Is there something wrong with using NR here? But putting a number there doesn't seem to help. I tried with 2 instead of NR but (same list as above) but still I get:

2
2

Is there a problem with the division I'm making?

Edit: I just echoed data and the output comes in one line 1 2 1 2 so probably is has something to do with my problem.