Calculate the sustainable growth rate for a company with a return on equity (ROE) of 20% and a dividend payout ratio of 40%. Discuss the significance of the sustainable growth rate in financial planning and forecasting. Analyze how the SGR reflects the maximum rate at which a company can grow its sales, earnings, and dividends without needing to increase its financial leverage. Consider the implications of exceeding the SGR, such as the need for additional financing and the potential impact on financial stability. Discuss the strategic importance of managing growth in line with the SGR, including maintaining a balance between reinvesting earnings and paying dividends. Explain how the SGR can be used in conjunction with other growth metrics to support long-term strategic planning and decision-making.