calculate mean in a for loop

i wish to calculate mean for every additional column (eg.for first row; calculate mean for column 1 store in (1,1), for column 2 calculate mean for first 2 columns store in (1,2), for column 3 calculate mean for first 3 columns store in (1,3) and so on) for each of my rows independently.

I have a 600x200 matrix (data) and I have tried using nested for loops so that the calculation is done for all 600 rows but my results are incorrect. grateful for any ideas. a part of my code looks like this;

m=600
n=200
for k=1:m
    for h=1:n
    Mean_answer(k,h)= mean(data(1:h))    
    end 
end

Answer 1

[Image Analyst]

You need to specify the kth row of data

Mean_answer(k, h)= mean(data(k, 1:h))  

[Rogers Tuyisenge]

Thanks mate, this fixes the problem!

Answer 2

[Matt J]

No need for loops,

Mean_answer=cumsum(data,2)./(1:size(data,2));

[Rogers Tuyisenge]

Thanks Matt, working on other stats too so just wanted all of them in a loop