The following is a series of annual sales (in millions of dollars) over an 11-year period (2000 to 2010): Year: 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 Sales: 13.0 17.0 19.0 20.0 20.5 20.5 20.5 20.0 19.0 17.0 13.0 a. Construct a time-series plot. b. Does there appear to be any change in annual sales over time? Explain.
Please show me how to do this.