Convergence rate

Jun 2010
15
0
I have the following sequences of numbers:
1) 32, 16, 8, 4, 2, 1
2) 32, 16, 8, 2, 1, 0.5
3) 32, 16, 4, 2, 1, 0.5,
4) 32, 16, 4, 1, 0.25, 0.0625

I'm interested which of the above has the fastest rate of convergence.
(mathematical formula is needed). I should be able to plot the rates of
convergence against each other, and it should be concluded from the plot.
(The data given above are just the illustration)
 
Jun 2010
15
0
This means I should be able to tell which sequence drops/decreases faster from the plot.
For example, given sequences {32, 16, 8, 4, 2, 1} and {128, 32, 8, 2, .5, .125} I should be able to tell that the second sequence drops faster (decreases by /4). How to extract this data and plot it, so that the answer is obvious? Thanks