Answer:
In the 23rd year his income was of $33,900.
Explanation:
Joe's income has been increasing each year by the same dollar amount.
This means that his salary after t years is given by:

In which S(0) is the initial salary and a is the yearly increase.
The first year his income was $22,000
This means that
. So


In the fourth year his income was $24,100
S(4) = 24100, and thus, we use this to find a.





So

In which year was his income 33,900
This is t for which S(t) = 33900. So





Rounding up, in the 23rd year his income was of $33,900.