Five employees earn 18, 19, 20, 21 and 90 thousand per year. The manager wants the average that best represents a typical salary in this group rather than one that the single very high salary inflates. Enter that average in thousands per year.

Explication

Placing the five salaries in order puts 20 thousand in the middle, and that figure sits inside the band of ordinary salaries where four of the five employees actually are. Dividing the total of 168 thousand by 5 returns 33.6 thousand instead, but four employees earn less than that, so it describes nobody in this group and is exactly the figure the single salary of 90 thousand has inflated.