I did an experiment measuring the intensity of light in relation to the distance away from a source. How would I graph the avg intensity over 1/distance squared?
Note that T1 = trial 1 etc.. 
It's supposed to look something like this showing exponential decay, with the values obviously being adjusted based on my results.
Any help would be much appreciated, regards.
You will get a very different graph from the one you have drawn for intensity against distance if you plot intensity against $\cfrac 1{\text{distance}^2}$
What you seem to be trying to do is to use the numbers in your final column on the $x-$ axis, which will then run up to a maximum value of $\cfrac 1{25}=0.04$, so you might choose a scale which goes from $0$ to $0.05$.
The $y-$ axis should reflect the numbers in the fifth column.
It seems possible that you are doing an exercise to convert the kind of graph you have shown (which is equivalent to having the first column on the $x-$ axis) to a straight line.
Does this help any?