# Creating chart in Excel where data for X-axis (horizontal) is non linear and extrapolating value

Have some data of the following form:

``````  X |  Y
----+-----
3 |  42
4 |  57
6 |  92
11 | 119
19 | 316
``````

(NOTE: The above table is made-up data)

What I'd like to do with MS-Excel is to plot 2 curves, one that treats values in col. 'X' as horizontal axis data, assuming it to be a linear scale, and another assuming it to be a logarithmic scale. Is this possible ? If so, how ?

Also, if I wish to extrapolate the value of Y, (using, what I hope would be a choice of multiple "models"), for a given value of X, s.a. X = 5 or X = 9, how can I do it ?

I'd believe this to be the typical curve-fitting problem, with the statistical extrapolation, but don't know enough of MS-Excel to get around.

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FYI, I flagged this question because you asked two different questions in it. I recommend separating the two for better quality answers. – dav Jan 23 '14 at 13:24
Reason I didn't split is that the seemed fairly related ! – jay Jan 23 '14 at 14:59

You've asked two different (albeit related) questions here. You should consider splitting this into two separate questions.

1. Create your chart as a Scatter (XY) Type.
2. Adjust your axis (for min/max limits) and any other formatting you desire.
3. Select this first chart and choose copy.