Is there a way to get a histogram chart in excel with two series, each
with different X values?

for e.g.

Series1
a 10
b 20
c 30
d 40


Series 2
a 100
d 400
b 200


(assume 1st column represents X values and 2nd column represents Y
values)

note that though some X values are the same in both series, there are
some inconsistencies.

is there a way to get a histogram chart in excel, which would
automatically put together the things that belong to the same X ?

Thanks