The data in the table give the total numbers of prisoners executed in the United States from 1984 to 2013.
(a) Construct a bar graph with x as the years (in groups of 5) and with f(x) as the number of prisoners executed.
(b) Find the mean number of executions per year.
(c) Find the standard deviation of the number of executions.
(d) Does the standard deviation indicate that there is little variation over the years?

Total Year Total Year Year Total 1984 21 1995 56 2006 53 1985 1986 2007 42 18 1996 45 1997 18 74 2008 37 2009 52 1987 25 1998 68 1999 1988 11 98 2010 46 1989 16 2000 85 2011 43 2001 1990 23 66 2012 45 2002 2013 39 1991 14 71 1992 31 2003 65 1993 38 2004 59 1994 31 2005 60