Q3: [16]TV Commercials The mean duration of television commercials on a given network is 75 seconds, with a stan- dard deviation of 20 seconds. Assume that durations are approximately normally distributed. (a) [5]What is the approximate probability that a commercial will last less than 35 seconds? (b) [5]What is the approximate probability that a commercial will last longer than 55 sec- onds? (c) [6]Can you use Chebyshev's Theorem to describe the data? Why or why not? If yes, use Chebyshev's Theorem to make a statement about the percentage of commercials that lasts between 45 and 105 seconds