MATLAB: How to vectorize this loop

Question

   for i=1:length(v) %for each numer from 1 to length of arry
    if(i==1) %1/1 = 1
        cumavg(i)=v(i);
    else
        cumavg(i)=0;
        for j=1:i
            cumavg(i)=cumavg(i)+v(j);
        end
        cumavg(i)=cumavg(i)/i;
    end
    if(cumavg(i)<= (avg-0.01))
        mark=i;
    end
end

Answer 1

cumavg = cumsum(v)./(1:numel(v));
mark = find(cumavg<=(avg-0.01),1,'last');