"The Matlab way"...
Rateall= 0.5.*(log2(1+SINR1).+log2(1+SINR2));
distanceall=pdist([randomclusters{:,1};randomclusters{:,2}],'euclidean');
presuming SINR1 and 2 are vectors; otherwise and in your code you have only a constant and a single value for all results as there's nothing dependent on 'i' in the expression otherwise.
Similarly for the other with randomclusters