Convert a Power Trendline into Data

[Cazzy B]

Hi - hoping someone can help me, I'm really struggling!

I have some data which I have plotted into a graph and created a power trend line.

I want to have the data that creates the power trend line in a table.

I have found formulas - but I just don't seem to be smart enough to put them into practice. Can anyone help me?

This is my original data;

DATA
Quantity	Price
100	70.07
200	101.33
300	215.6
400	280.19
500	283.51
500	62.52
1000	457.65
1000	457.65
1000	381.83
1000	295.37
1000	280.19
1500	338.49
1500	338.49
2000	458.15
2000	352.9
2000	332.02
2000	330.03
2550	267.34
3000	717.61
3000	555.17
3000	467.85
4000	1020.9
4000	773.65
4900	562.16
6000	365.44
8000	512.05
50000	1293.6

<colgroup><col width="46" style="width: 35pt; mso-width-source: userset; mso-width-alt: 1682;"> <col width="46" style="width: 35pt; mso-width-source: userset; mso-width-alt: 1682;"> <tbody> </tbody>

This is my graph with power trend line.

-- removed inline image ---


This is the table that I want to complete with the trend line data (up to 50,000)

Quantity	Price
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127

<colgroup><col width="64" style="width: 48pt;" span="2"> <tbody> </tbody>

This is the equation that I found;

Equation: y=c*x^b
c: =EXP(INDEX(LINEST(LN,LN(x),,),1,2))
b: =INDEX(LINEST(LN,LN(x),,),1)

<colgroup><col width="46" style="width: 35pt;" span="2"> <col width="82" style="width: 62pt; mso-width-source: userset; mso-width-alt: 2998;"> <col width="46" style="width: 35pt;" span="3"> <tbody> </tbody>

Can anyone help me put this into practice?

 

[Cazzy B]

Got it! Many thanks

 

[Cazzy B]

Hi Mr Excel.

For some of my data sets I need to use the Linea Trendline. Do you know the formula I would need in cell E2 to do this please?

Many Thanks

 

[Andrew Poulsom]

That's:

=FORECAST(D2,B2:B28,A2:A28)

 

[Cazzy B]

Thank you - this is perfect - please can I trouble you (last time) for the formula that would convert a polynomial trendline as well?

 

[Andrew Poulsom]

Look here:

Spreadsheet Page Excel Tips: Chart Trendline Formulas