Average functions showing wrong value in table

[ankuragrawal]

192.87+190.52=383.39

383.39/2=191.69

Please help

[mikaelsc]

https://math.stackexchange.com/questions/95909/why-is-an-average-of-an-average-usually-incorrect

total average is not average of the totals (per line)... (depends on the number of values... )