ANSWER:
175.8 pounds
STEP-BY-STEP EXPLANATION:
We have that Finn's weight is given by the following function:
[tex]f(x)=193.9-1.1x[/tex]Where x is the elapsed days, then to calculate its weight 16.5 days later, we must replace the value of x, just like this:
[tex]\begin{gathered} f(16.5)=193.9-1.1\cdot16.5 \\ f(16.5)=175.75\cong175.8 \end{gathered}[/tex]Finn's weight after 16.5 days is 175.8 pounds