CombiStatX

CombiStatX is a programm that lets you carry out two useful statistical procedures.
Firstly, you can combine several Mean±SEM values into an overall Mean±SEM.

Secondly, you can calculate the Standard error (SE) and Standard deviation (SD) of the ratio (X/Y), product (X*Y), sum (X Y), and difference (X-Y) of the mean values (X and Y) of two independent variables, x and y, each with an associated SEM.