background:

I import data into my excel worksheet from a call logging database and use
excel to create graphs for statistics etc, this works fine, however I want to
generate a graph that shows the call resolution times i.e the amount of
hours/min between a call being logged and closed. I have generated the
resolution times using formula to calculate the difference between two
dates/times.

Problem:

I select the data range and click on the create chart button, but no matter
what chart type I select, the graph is pretty much blank with just a single
figure/value showing "1". The data I have selected is as follows....

1:09
1:08
0:20
0:06
0:29
2:58
2:52
2:49

As you can see the amount of data is not huge and is simple enough, any
ideas as to why the graph wont show the values?

Problem 2:

Also as a seperate issue I am unable to calculate an average on the above
values, whichever average formulae I use it generates an error e.g
=AVERAGE(R4:R11) or =AVERAGEA(R4:R11)

Any helps appreciated.