(3) Suppose that the market for silk-screened T-shirts grew by \(10\%\) during 2019. All increases in sales greater than \(10\%\) are the result of Hulk's strategic actions. Calculate the change in operating income from 2018 to 2019 due to growth in market size, product differentiation, and cost leadership. How successful has Hulk been in implementing its strategy? Explain. \((4\%)\)