hi!

i was asked to calculate the RMSre between my reference and estimated data and i have simply no clue how to do this...
i think that the RMSre is somthing similar to the root mean square error (RMSE) right???
can somebody tell how to calculate this in excel??? for example, i now that for the RMSE i have to apply the following formula:

=SQRT((SUMXMY2(estimated data sum,reference data sum))/COUNT(number of estimated data fields))

can someone provide with a similar formula for excel please??? can you also write the formula using the language i used above???
thank you in advance!!!