The task is the following:

" What is the temperature:

During atmospheric reentry in 35 km height, if there t0 = –40°C? You can determine the velocity from the data of the graph by using interpolation. (The data is the reentry speed of the Space Shuttle in different heights).

The data:

H=75km->v=7,68m/s

H=47km->v=6,24m/s

H=25km->v=0,95m/s

H=35km->v=???"

I have all the formulas to solve the rest of the task, but the only thing I can't solve is the velocity by using interpolation.

If this would be linear interpolation, I could figure it out, but since it can't be linear, I have no idea how to solve it. If someone could share a formula or just some ideas that I can use to determine the missing data, that would be a great help for me.