loop for sum and average for specific rows

Dear All

I have sea level data 300*1, it is monthly data for 25 years, the data in Excel file

Describing the row (1 JAN, 2 Feb, 3 Mar........ 12 Dec, 13 JAN, 14 Feb, 15 Mar............ 300 Dec )

I want to use a loop to work (sum and average each month) and the final result will be 12*1

Many Thanks in advance

Answer 1

[KSSV]

A = rand(300,1) ; 
B = reshape(A,12,[]) ; 
thesum = sum(B,2) ; 
themean = mean(B,2) ; 

[nada]

All thanks and appreciation KSSV