The range of numbers in a compression test may differ depending on the equipment used. A different shop's equipment may show all cylinders to be around 180, or 190, or even above 200. It's the similarity between these numbers that affirms an engine's health.
For eg, one shop tells you the compression is 160 - 150 - 160 - 160.
This translates to cylinder # 2 as being weaker then the other cylinders.
On the same engine, a different shop would show 190 - 170 - 190 - 190.
Same thing, cylinder # 2 is weaker.
The deviation between the numbers matter, not the actual numbers.