(25 points) The following table compares U. S. population (millions) with U. S. per-capita consumption of bottled water (gallons).
[Source: Bureau of the Census, Statistical Abstract of the United States 2009, pp. 10, 134.]
Year
x=U. S.Population y=Per-Capita Consumption of Bottled Water
2002
287.9 million
20.1 gallons
2003
290.4
21.6
2004
293.2
23.2
2005
295.9
25.5
2006
298.8
27.6
1. (10 points) Determine the least-squares regression line and the value of r.
2. (5 points) Compute a 95% confidence interval for mean of the per capita
consumption of bottl water, given the U. S. population is 320 million.
3. (5 points) Compute a 95% prediction interval for an individual observation of
per capita consumption of bottled water, given the U. S. population is 320
million.
4. (5 points) Compare the confidence interval and prediction interval. Which one is
wider? And why?
You may use the critical values as below: t(0.025,3)= 3.182446, t(0.025,4)=2.776445.