Extrapolation Calculator

Originally Posted by sinikiwep

Can u please help me with extrapolating these figure. I have attached the table with the values and have a red font for what I need help on. [....] Attachment 324206

Put the following formula into B25:

=FORECAST(A25,$B$4:$B$24,$A$4:$A$24)

Note: I do not recommend using FORECAST or any method of extrapolation arbitrarily. Before I used FORECAST, I charted the values in A4:A24 and B4:B24 and used the trendline feature to confirm that the data does indeed approximate a linear relationship.

Or you could calculate slope and intercept and use the equation
y = mx+b
SLOPE = SLOPE(y range, x range)=m
Intercept = INTERCEPT(y range, x range) =b
correlation coefficient = CORREL(y range, x range)
R squared = RSQ(y range, x range)

FORECAST() can be a useful function for empirical extrapolation. The data you have are quite linear, so it might be acceptable (if a purely empirical approach is acceptable).

Personally, I would probably do something a little more rigorous. PV=znRT. density (n/V) is essentially constant, compressibility (z) can be calculated from an EOS (see NIST, if you don't have an EOS calculator http://webbook.nist.gov/chemistry/fluid/). This will better demonstrate an understanding of PVT properties of gases.

True, depends on what he wants to gleam from his data. FORECAST is certainly the shortest route to the answer.