If you must perform a direct lookup (not recommended for dynamic spreadsheets), you would:
Use INDEX and MATCH or XLOOKUP with approximate match:
=XLOOKUP(1, (Density_Range = Round_Density) * (Temp_Range = Round_Temp), VCF_Range, , 0)
But beware: rounding density and temperature to the nearest table increment introduces measurable errors for custody transfer.
In cell B6, enter:
= (341.0977 / ((B2/1000)^2)) + (-0.69859 / (B2/1000)) + 0.001373
Note: We divide B2 by 1000 because the constants expect density in g/cm³ (e.g., 0.830, not 830).
Before diving into Excel mechanics, it is crucial to understand the underlying physics.