Answer
The function represents exponential decay.
Work Step by Step
The given function is
$r(t)=(0.88)^{4t}$
Use power of powers property.
$r(t)=(0.88^{4})^{t}$
Evaluate the power and simplify.
$r(t)=(0.60)^{t}$
$r(t)=(1-0.40)^t$
Hence, the function represents exponential decay.
