Refer to the previous exercise. Using regression, the prediction equation relating GDP (in thousands of dollars per capita) to carbon dioxide emissions (in metric tons per capita) is
(a) What type of pattern would you expect for the points
in a scatterplot for these data?
(b) In this data set, the highest CO2 value was 17.0
metric tons, for the United States. Its GDP was 53.1. Find its predicted CO2 use, according to the regression analysis.
(c) In this data set, GDP ranged from a low of 4.4 to a high of 62.9. Find the range of predicted values.
For 2014World Bank data (data.worldbank.org) for several nations, a prediction equation relating fertility (the mean number of children per adult woman) and percentage of people using the Internet is
Predicted fertility = 3.20 âˆ’ 0.02(Internet use).
(a) Compare the predicted fertility of a nation with 87% use of the Internet (Canada) to a nation with 0% use (North Korea).
(b) The correlation is âˆ’0.55. Explain what the negative value represents.
(c) The correlation for these nations between fertility and percentage of people using contraceptive methods is âˆ’0.89. Which variable seems to be more strongly associated with fertilityâ€”Internet use, or contraceptive use? Why?