Year | Tornadoes | Census |
1953 | 421 | 158956 |
1954 | 550 | 161884 |
1955 | 593 | 165069 |
1956 | 504 | 168088 |
1957 | 856 | 171187 |
1958 | 564 | 174149 |
1959 | 604 | 177135 |
1960 | 616 | 179979 |
1961 | 697 | 182992 |
1962 | 657 | 185771 |
1963 | 464 | 188483 |
1964 | 704 | 191141 |
1965 | 906 | 193526 |
1966 | 585 | 195576 |
1967 | 926 | 197457 |
1968 | 660 | 199399 |
1969 | 608 | 201385 |
1970 | 653 | 203984 |
1971 | 888 | 206827 |
1972 | 741 | 209284 |
1973 | 1102 | 211357 |
1974 | 947 | 213342 |
1975 | 920 | 215465 |
1976 | 835 | 217563 |
1977 | 852 | 219760 |
1978 | 788 | 222095 |
1979 | 852 | 224567 |
1980 | 866 | 227225 |
1981 | 783 | 229466 |
1982 | 1046 | 231664 |
1983 | 931 | 233792 |
1984 | 907 | 235825 |
1985 | 684 | 237924 |
1986 | 764 | 240133 |
1987 | 656 | 242289 |
1988 | 702 | 244499 |
1989 | 856 | 246819 |
1990 | 1133 | 249623 |
1991 | 1132 | 252981 |
1992 | 1298 | 256514 |
1993 | 1176 | 259919 |
1994 | 1082 | 263126 |
1995 | 1235 | 266278 |
1996 | 1173 | 269394 |
1997 | 1148 | 272647 |
1998 | 1449 | 275854 |
1999 | 1340 | 279040 |
2000 | 1075 | 282224 |
2001 | 1215 | 285318 |
2002 | 934 | 288369 |
2003 | 1374 | 290447 |
2004 | 1817 | 293191 |
2005 | 1265 | 295895 |
2006 | 1103 | 298754 |
2007 | 1096 | 301621 |
2008 | 1692 | 304059 |
2009 | 1156 | 308746 |
2010 | 1282 | 309347 |
2011 | 1691 | 311722 |
2012 | 938 | 314112 |
2013 | 907 | 316498 |
2014 | 888 | 318857 |
Is the number of tornadoes increasing? In thelast homework, data on the number of tornadoes in the United Statesbetween 1953 and 2014 were analyzed to see if there was a lineartrend over time. Some argue that it’s not the number of tornadoesincreasing over time, but rather the probabilityof sighting them because there are more people living in the UnitedStates. Let’s investigate this by including the U.S. census count(in thousands) as an additional explanatory variable (data inEX11-24TWISTER.csv).
Fit one SLR model with year as the predictor, another SLR modelwith census count as the predictor. Write down the two models. Areyear and census count significant, respectively?