Extrapolation

venkat635 

TREND function

https://support.microsoft.com/en-US/office/trend-function-e2f135f0-8827-4096-9873-9a7cf7b51ef1

Calculate the linear trend line to the arrays of known_y’s and known_x’s

https://corporatefinanceinstitute.com/resources/excel/functions/forecast-trend-extrapolate-excel/

etxrapolation => straight line equation = in two-point form

interpolation => straight line equation or calculated polynomial within the interpolation points.

extrapolation:
Here is an example from the Internet, shown more clearly and simply / corrected. This means you are now going to the series of results
and expands this by (70 ... 110) and calculate the corresponding x-values.

interpolation:
The determined polynomial could also be used approximately within the given XY values,
or, two-point form of the straight line equation. As is easy to see, the polynomial runs out of control outside the specified XY values and becomes too imprecise.

My answers are without knowledge, voluntary and without guarantee!

I would be happy to know if I could help.

Nikolino
I know I don't know anything (Socrates)