What Jerry means is don't use a column chart. It is the wrong kind of chart
to use to show relationships between two variables, even if you are not
trying to generate statistics on it. Rebuild the chart and select one of the
XY subtypes in step 1 of the chart wizard, or convert the chart using Chart
Type on the Chart menu. There's no need to mess around with the data range.

- Jon
-------
Jon Peltier, Microsoft Excel MVP
Peltier Technical Services
Tutorials and Custom Solutions
http://PeltierTech.com/
_______

"Jan M." wrote in message
...
Jerry,

I think I've figured out what your meant by "xy scatter"!
I modified my data table the following way and got the right results:

X Y
73 6.6
74
75
76
77
78 5.8
... ...

Thanks for your help.

Jan M.



"Jerry W. Lewis" wrote:

Use an "XY (Scatter)" chart.

When you selected a "Line" chart, you (by definition) told Excel that
your
x-axis was categorical instead of numeric, and that what you provided for
the
x-axis was a set of category labels that may or may not have numeric
values.
Why Excel would offer to fit a trendline in that circumstance is a
mystery to
me, but when it does, it uses x-values of 1,2,3,... and correctly
calculates
the regression of y against those assumed x-values.

Jerry

"Jan M." wrote:

Hi,

I created a bar chart in Excel from the following data:

X Y
73 6.6
78 5.7
86 4.8

The SLOPE and the INTERCEPT functions returned -0.136 and 16.4448
respectively. The resulting equation is Y = -0.136X + 16.448 which
seems good
enough to me.

Then I added a linear trendline to the chart. Excel displayed the
following
equation: Y = -0.9X + 7.5, R ^2 =1 which is way off (and it's not a
rounding
problem)!!!

The data seemed farly linear to me, how come Excel can't come up with
the
right equation???

Thanks

Jan M.