Saving data from for loop

Hi have been trying to save the data from my for loop each time it runs but for some reason it given the 3 number that i need but with also a lot of other zero in the matrix. Idont know what I'm doing wrong):

 for x=30:20:70

   for y = 2:2:6
        Energy = x*0.239;%covert cal to j
        Y= y*60;
        power = Energy/Y;
        Power(x)=[power];

    end
end

Answer 1

[KSSV]

x=30:20:70;
y=2:2:6;
power = zeros(length(x),length(y));
for i=1:length(x)
   for j=1:length(y)
        Energy = x*0.239;%covert cal to j
        Y= y*60;
        power(i,j) = Energy/Y;
    end
end

Answer 2

[Jan]

Without the loop:

x      = 30:20:70;
y      = 2:2:6;
Energy = x * 0.239; %covert cal to j
Y      = y * 60;
Power  = bsxfun(@rdivide, Energy, Y.');

[KSSV]

I think for beginners loops are good so that they can learn coding and then go to next level.