Average of 2 columns within a 3 column matrix

I have a matrix X with dimensions [288 192 60] or [lat lon time]. I want to find the average value of the first two columns to get a matrix that is just [space time] or [1 60] (aka a single average value of space for each unit time).

I tried:

X = mean(X,[1 2],'omitnan');

X = X(:,:);

But this seems to not be giving me correct values. Does anyone know the correct way to do this?

Answer 1

[David Hill]

for k=1:60
  x(k)=mean(X(:,:,k),'all','omitnan');
end