Creating Histogram by Classification

[rayyylife]

I want to create a histogram by classification that will update when I add new values.

So say I have a classification of
A, B, C, D

And numbers that correlate such as
A - 200
A - 140
B - 34
B - 56
C- 100
etc... (There is lots of these)

How can I make a histogram that will be like...
Of all the A's this is your histogram
Of all the B's, this is your histogram

As well as update as I enter new numbers (some of them are blank at the moment and as I find the numbers, I want the graph to update)


Please let me know the steps if this is possible or just the next best idea to graphing these.

Thanks!