Linest/ create poly curve

[Henk2017]

Hello,

I would like to see that the increase of the values fit a polynomial curve and this increase is calculated by excel.
For example:

X	Y
1	100
2	Calculated by excel
3	Calculated by excel
4	Calculated by excel
5	Calculated by excel
6	140

Does someone know how to calculate the [Calculated by excel] values with a formula and that the result fit a polynomial trend?

 

[Henk2017]

Hello,

I would like to see that the increase of the values fit a polynomial curve and this increase is calculated by excel.
For example:

X	Y
1	100
2	Calculated by excel
3	Calculated by excel
4	Calculated by excel
5	Calculated by excel
6	140

Does someone know how to calculate the [Calculated by excel] values with a formula and that the result fit a polynomial trend?

I should add:
- the user of the file will change the values of 100 and 140 (1 and 6).
- 1 and 6 will not change i.e. it always ranges from 1 to 6.