.
If you will read the formulas in the post by @Penguin, it may happen that you will need an urgent medical help ---
so incorrectly and carelessly they are presented.
Therefore, to avoid such a sad final, I post here my correct solution, which you may read safely.
P = $22395
R = 4.09%
n = 12 months
t = 4 years
A = = = $26368.22
Solved (in a correct and safe way).