Answer
No.
The percentage of movie advertising in the total newspaper advertising revenue spiked (made a sudden jump) in 1999.
Work Step by Step
In part (a), we found that the one-sided limits exist, but are not equal.
Thus, a limit at $t=4$ does not exist, meaning that the function has a discontinuity at t=4.
Interpretation:
The percentage of movie advertising in the total newspaper advertising revenue spiked (made a sudden jump) in 1999.
