The below data shows the percentage of adults who were smokers in the years between 1965 and 2014. Year Smokers 1965 41.9 1970 37.4 1974 37.1 1978 34.1 1980 33.2 1983 32.1 1985 30.1 1987 28.8 1990 25.5 1993 25 1995 24.7 1997 24.7 1999 23.5 2001 22.8 2002 22.5 2004 20.9 2006 20.8 2008 20.6 2010 19.3 2012 18.1 2014 16.8 a) Make a scatterplot of these data. (8 marks) b) Describe the direction, form and strength of the relationship between percentage of smokers and year. (5 marks) c) Find the least-squares regression line for the data. (7 marks) d) What percent of the observed variation in percent of adult who smoke can be explained by the linear change over time