Open the file Coal_Consumption containing data from the U.S. Energy Administration.
a. Make a scatter graph of the data with a trendline. Copy and paste your graph here.
b. Use your model (the trendline equation) to predict coal consumption in the year 2017. How confident are you in this prediction? Why?
c. According to your model, when will the coal consumption be 1600 short tons? How confident are you in the above prediction?
d. Beside the R-squared value and the time gap, what are some social, political, or physical factors that could affect the accuracy of these prediction? Do you think these factors will lead to an increase or a decrease in coal consumption in the future?
|
Year
|
Coal Consumption (in short tons)
|
|
1970
|
523.23
|
|
1971
|
501.57
|
|
1972
|
524.26
|
|
1973
|
562.58
|
|
1974
|
558.40
|
|
1975
|
562.64
|
|
1976
|
603.79
|
|
1977
|
625.29
|
|
1978
|
625.22
|
|
1979
|
680.52
|
|
1980
|
702.73
|
|
1981
|
732.63
|
|
1982
|
706.91
|
|
1983
|
736.67
|
|
1984
|
791.30
|
|
1985
|
818.05
|
|
1986
|
804.23
|
|
1987
|
836.94
|
|
1988
|
883.64
|
|
1989
|
895.00
|
|
1990
|
904.50
|
|
1991
|
899.23
|
|
1992
|
907.65
|
|
1993
|
944.08
|
|
1994
|
951.29
|
|
1995
|
962.10
|
|
1996
|
1006.32
|
|
1997
|
1029.54
|
|
1998
|
1037.10
|
|
1999
|
1038.65
|
|
2000
|
1084.09
|
|
2001
|
1060.15
|
|
2002
|
1066.35
|
|
2003
|
1094.86
|
|
2004
|
1107.25
|
|
2005
|
1125.98
|
|
2006
|
1112.29
|
|
2007
|
1128.00
|
|
2008
|
1120.55
|
|
2009
|
997.48
|
|
2010
|
1048.51
|
|
2011
|
1002.95
|
|
2012
|
889.19
|
|
2013
|
924.83
|