Marlboro ' 75 ' 60 ' 23.5 Camel 43 13.3 6.7 Newport " 35 " 12.7 ' 4.8 Kool ' 21 ' 1.2 ' 3.9 Winston 17 1.2 3.9 Benson & Hedges 4 1 3 Salem ' 3 ' 0.3 ' 2.5 a. Explore the possibility of a linear relation between advertising and brand preference for adults and for adolescents separately. Do there seem to be strong linear relationships, based on a scatter plot and the correlation? b. Build linear models to represent the relation between advertising and brand preferences for these two groups. What preferences would the models predict for advertising of $60 million