Answer
$y=20,000(0.866)^t$
Work Step by Step
Initial value $a=\$20,000$
Rate of decay $r=13.4\%=0.134$
The exponential decay function is
$\Rightarrow y=a(1-r)^t$
Substitute $20,000$ for $a$ and $0.134$ for $r$.
$\Rightarrow y=20,000(1-0.134)^t$
Simplify.
$\Rightarrow y=20,000(0.866)^t$.
