14.18 Global warming. Have average global temperatures been increasing in recent years? Here are annual average global temperatures for the last 21 years in degrees Celsius.
(a) Make a scatterplot. (Which is the explanatory variable?)
(b) Is the association between these variables positive or negative? Explain why you expect the relationship to have this direction.
(c) Describe the form and strength of the relationship.
| Year | 1994 | 1995 | 1996 |
| Temperature | 14.23 | 14.35 | 14.22 |
| Year | 1997 | 1998 | 1999 |
| Temperature | 14.42 | 14.54 | 14.36 |
| Year | 2000 | 2001 | 2002 |
| Temperature | 14.33 | 14.45 | 14.51 |
| Year | 2003 | 2004 | 2005 |
| Temperature | 14.52 | 14.48 | 14.55 |
| Year | 2006 | 2007 | 2008 |
| Temperature | 14.50 | 14.49 | 14.41 |
| Year | 2009 | 2010 | 2011 |
| Temperature | 14.50 | 14.56 | 14.43 |
| Year | 2012 | 2013 | 2014 |
| Temperature | 14.48 | 14.52 | 14.59 |