Math for Available Compounds

I would like to confirm some calculations:

In the case there is a 1.162% Terpene profile I understand that the math would say that there is aprox 5.26g per lb

452.8g per lb
452.8 x 1.162% = 5.26 g per lb

If this is true. What have people found that the lab analysis are off as fat as % wise. In other words are they on an average of 3% off?

I am being told that an extractor pulled 7 grams per lb of a terpene blend off of 6 month old blended biomass that has not been sealed during storage. The lab test on the “bud”, 6 mo ago, showed 14% CBD. The new test on the “blended biomass” shows 8%. They did not have the terpenes tested.

Is it even possible to pull 7 grams per lb out of blended biomass? My calculations show that it would be difficult to even pull 7g per lb out of the best fresh bud with a very high terpene count.

Which terpenes were present?

On the first and second lab test results, what were the CBN percentages?