## standard error???

recently i have ran experiment which involving on determination of rate diffusion of liquid pollutants into carrier gas.

the result of my rate diffusion from my experiment:

theoretical rate diffusion : 0.093755208 cm2s-1

rate diffusion after 1st iteration :
 0.091610338cm2s-1

rate diffusion after 2nd iteration :
 0.091606291cm2s-1

rate diffusion after 3rd iteration :

 0.091606291cm2s-1

rate diffusion after 4th iteration :
 0.091606291cm2s-1 (iteration procedure is stopped since the value coincides with the previous one)

*iteration involving the treatment of raw experimental data using specific formula so that experimental diffusion rate get close to the theoretical diffusion rate

in the journal for the same experiment states that the data for the rate diffusion must be presented with "standard error" by regression method... what is that mean???? can i just use Microsoft excel 2007 to calculate the standard error???

my question is - is theoretical rate diffusion involve in calculating "standard error"??? or it just enough by using the iteration values of rate diffusion???