A Calculate Return on Common Equity (ROCE) for Fiscal X4

$\begin{array}{|l|r|r|}\hline \text { Long-term debt } & 7,709 & 8,508 \\\hline \text { Long-term obligations under capital leases } & 2,307 & 2,092 \\\hline \text { Deferred income taxes and other } & 463 & 400 \\\hline \text { Minority interest } & 1,025 & 331\\\hline \\\text{Shareholders' equity:}&&\\\hline\text{Preferred stock (\$ 10 par value, 100 shares authorized, none issued)}&&\\\hline\text{Common stock (\$ .10 par value, 5,500 shares authorized, 2,285 and}&&\\\hline 2,293 \text{ issued and outstanding in X6 and X 7, respectively)} & 228 & 229 \\\hline \text{Capital in excess of par value}& 547 & 545 \\\hline \text{Retained earnings} & 16,768 & 14,394 \\\hline \text{Foreign currency translation adjustment} & \underline{(400)} & (412)\\\hline\text{ Total shareholders' equity} & \underline{17,143}&\underline{14,756}\\\hline \text{Total liabilities and shareholders' equity} & \$ 39,604 & \$ 37,541 \\\hline\end{array}$
a. Calculate return on common equity (ROCE) for fiscal X4 and X7. Identify, as far as allowed by the data, components driving any changes in ROCE from X4 to X7. (If you want to give students more guidance then ask to disaggregate ROCE into net operating profit margin, net operating asset turnover and leverage.)
b. Compare and contrast the change in earnings per share to ROCE over this time period.