This should be easy - but I'm having trouble with it. I have columns A and B
with data like this:

A B

X 5
X 2
Y 1
X 4
Y 3

I want column C to be the total for the table of the value in A. So column
C should have

11
11
4
11
4

Since wherever there is an X in column A the total of the X's is 11(5+2+4),
and wherever there is a Y in column A the total of the Y's is 4 (1+3). I
would appreciate the formula for column C - thanks for any help on this.