Class 27 Example: Height and Weight Case: Colonial Broadcasting(HBS: 9-894-011)
Heights and Weights of n=30 11-year-old girls Al used the regression of KG on CM to forecast the weight of a girl 144.8 cm tall. Al’s point forecast was _______________ Sample Means
The regression line Always goes thru Any three can be used to find the fourth.
Heights and Weights of n=30 11-year-old girls Bo regressed KG on inches. Which model will be the better predictor of KG? Al’s Bo’s They should give identical results. Sample Means
Colonial Broadcasting Company • Three Networks • ABN, BBS, CBC • Data from 88 made-for-TV movies (1992) • CBC wants to know what factors affect the movie’s Rating. (the percent of US households with TVs tuned into a program) • CBC needs to forecast the rating of a proposed movie.
1a. Rank the networks based on average 1992 rating. 1b. How big was the ratings gap between the top and bottom ranked networks?
2a. What is the average rating of fact based movies? 2b. Is the difference in fact and fiction ratings statistically significant?
3. Which is most true? fact-based movies had fewer stars (than fictional movies) Fact-based movies had more stars. Fact-based movies had the same number of stars. Cannont be determined.
4. On Sunday night, CBC usually airs “Josette and Yvette” at 8 pm followed by the Sun night movie. “J&Y” typical get a 17.5 rating. If they replace “J&Y” with a rock concert expected to get a rating of 20, what is the expected change in the movie rating?
5. A high-ranking CBC exec argued that network programming does not affect total size of network audience, only the relative share each network receives. Does the regression support or refute this assertion?
6. BBS’s new movie is fiction- based with 2 stars. We don’t know when it will be aired. Will it’s rating exceed the 1992 average for BBS movies?