request to assist in solving the below

A firm's financial data for 2004-2006 is given in this chart (all figures in 1000s of $). If the firm's average anual profits over the period 2004-2012 are $300,000, and its average costs and revenues change by an equal percentage between the two periods, what is the ratio of its revenue in 2004-2006 to its revenue for the years 2007-2012?

year 2004 2005 2006

cost 400 900 500
revenue 300 700 1100

choices:

1/6
2/9
1/4
2/5
1/2