To chk compression, what kind of psi number should i get. on 1992 Lexus SC300

My son was told that his engine was no good. The car will crank but will not start. I wanted to know what numbers to look for during a compression test.

Asked by for the 1992 Lexus SC300
A good rule of thumb for engine compression would be 150psi - cylinders should all be within 10% of each other.