Exercise Chp Basic Probability: The Wall Street Journal


The broadcast networks introduce new television shows each fall. In an attempt to get viewers interested in the new shows, television commercials are aired during the summer as part of promotional campaign conducted prior to the fall debuts. The networks then conduct surveys to see what percentage of the viewing public is aware of the shows. According to network sources, in the fall of 2001, 68% of viewers aged 18-49 were aware of the new series Criminal Intent, whereas only 24% of viewers aged 18-49 were aware of Inside Schwatz (Joe Flint, “Viewers Awareness of New Shows Rises,” The Wall Street Journal, August 20, 2001, B7).

  • Suppose that a random sample of 20 viewers aged 18-49 is selected. What is the probability that:Less than five of the viewers are aware of Criminal Intent?
  • Are the 68% and 24% figures quoted by networks best classified as a prior classical probability, empirical classical probability, or subjective probability?
  • 10 or more are aware of Criminal Intent?
  • all 20 are aware of Criminal Intent?

Taken from Levin et al, Business Statistics, A First Course (4e) © 2006 Prentice-Hall, Inc.


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