The plural error should be corrected to 'Dentists'' and the possessive error should be corrected to 'physician's'.
Step-by-step explanation:
The plural error in the given sentence is 'Dentist's'. It should be 'Dentists'' to indicate that the salaries belong to multiple dentists. The correct sentence should be:
Dentists' salaries range from about $74,000 to $190,000.
The possessive error in the given sentence is 'physicians'. It should be 'physician's' to show that the exception applies to a single physician. The corrected sentence would be:
With the exception of a physician, most other healthcare workers earn much less.