The percentages of Earth€™s land surface that is forested and worldwide carbon dioxide emissions are shown in Table 59 for various years. Let x be the percentage of Earth€™s land surface that is forested and y be worldwide carbon emissions (in billion tonnes). After removing two influential points, the exponential regression equation is = 106,140,092(0.617)x.

a. What is the y-intercept of the model? What does it mean in this situation?
b. What is the percentage rate of decay of carbon emissions per 1 percentage point increase in forestation, according to the model?
c. Remove the data points (31.4, 24.8) and (31.4, 25.7) and then find the coefficient of determination for the model. What does it mean in this situation?
d. On the basis of the coefficient of determination being so close to 1, a student concludes that deforestation causes an increase in worldwide carbon emissions. What would you tell the student?
e. Describe at least one possible lurking variable.

Transcribed Image Text:

Table 59 Percentages of Earth's Land SurfaceThat Is Forested and Worldwide Carbon Dioxide Emissions Carbon Dioxide Emissions (billion tonnes) Percentage of Earth's Land Surface That Is Forested 31.9 31.8 31.7 31.6 31.4 31.4 31.3 31.2 31.1 310 Year 1992 1994 1996 1998 22.7 23.7 24.8 25.7 30.7 33.6 2010