Answer
$\text{exponential decay;}$
$y$-intercept = $3$
Work Step by Step
Recall:
The exponential function $y=c \cdot b^x$ involves:
(1) an exponential growth if $b\gt1$.
(2) an exponential decay if $0\lt b \lt1$.
The given exponential function has $b=0.25$, which is less than $1$.
Thus, the function is an example of exponential decay.
The $y$-intercept of an exponential function can be found by setting $x=0$ then solving for $y$.
Hence, the $y$-intercept of the given function is:
\begin{align*}
y&=3(0.25^0)\\
y&=3(1)\\
y&=3
\end{align*}
