Go to www.morningstar.com and type in CCI (ticker symbol for Crown Castle International Corp.) in the quote search. Use the financial data aquired from morningstar to calculate Internal Growth Rate and Sustainable Growth Rate estimates for CCI.

Internal growth rate IGR: Maximum growth rate based on internal funding:

IGR = (ROA x RR) / ( - L0*/A0 - ROA x RR)

Sustainable growth rate SGR: Maximum growth rate based on external debt financing while maintaining the current debt to equity ratio:

SGR = (ROE x RR) / ( - L0*/A0 - ROE x RR )

Notes:

assume = 1

l0* divided by A0 where L0* is the sum of accounts payable and accruals and A0 is total assets