cisco's gross revenue(the percentage of revenue left after subtracting the cost of goods sold) was 70.1% of total revenue over a certain 4-year period. if the totall revenue was $5.4 billion for the first 2 years and $6.1 billion for the last 2 years, what was the equivalent annual worth of the gross revenue over that 4-year period at an interest rate of 20% per year?