Suppose that between 2018 and 2019 the market for Grey's special-purpose machines grew at 3%. All increases in market share (that is, sales increases greater than 3%) are the result of Grey's strategic actions.

Required
Calculate how much of the change in operating income between 2018 and 2019 is due to industry market-size factors, cost leadership, and product differentiation. How successful has Grey been in implementing its strategy? Explain.