Answer
See the explanation below.
Work Step by Step
Left-sided limit:$\qquad \displaystyle \lim_{t\rightarrow 4^{-}}f(t)=0.04(4)+0.33=0.49$
Right-sided limit:$\displaystyle \qquad \lim_{t\rightarrow 4^{+}}v(t)=-0.01(4)+1.2=1.16$
Interpretation:
Just before 1999 ($t=4$ years after 1995), advertising expenditures were approaching ${{\$}} 0.49$ billion. Shortly after 1999, advertising expenditures were close to ${{\$}} 1.16$ billion.
