Given:
Depth of river last year = 4.2 feet
It dropped 22% this year.
Let's find the depth of the river this year.
We have:
[tex]\begin{gathered} 4.2\text{ }\ast\text{ 22\% } \\ \\ =\text{ 4.2 }\ast\text{ }\frac{22}{100}=\text{ }0.924 \end{gathered}[/tex]The depth this year is:
4.2 - 0.924 = 3.276 feet
Therefore the depth of the river this year is 3.276 feet deep
ANSWER:
3.276 feet