Read the following texts and table with financial data from an S&P 500 earnings report carefully.Based on the question-answer history (if provided), answer the last question. The answer may require mathematical calculation based on the data provided.

Text: increase in dividends paid . free cash flow is defined as cash provided by operating activities less cash used in investing activities and dividends paid . free cash flow is not considered a financial measure under accounting principles generally accepted in the u.s . ( gaap ) by sec regulation g and item 10 of sec regulation s-k and may not be defined and calculated by other companies in the same manner . we believe free cash flow is important to management and investors in evaluating our financial performance and measures our ability to generate cash without additional external financings . free cash flow should be considered in addition to , rather than as a substitute for , cash provided by operating activities . the following table reconciles cash provided by operating activities ( gaap measure ) to free cash flow ( non-gaap measure ) : millions 2013 2012 2011 . <table class='wikitable'><tr><td>1</td><td>millions</td><td>2013</td><td>2012</td><td>2011</td></tr><tr><td>2</td><td>cash provided by operating activities</td><td>$ 6823</td><td>$ 6161</td><td>$ 5873</td></tr><tr><td>3</td><td>cash used in investing activities</td><td>-3405 ( 3405 )</td><td>-3633 ( 3633 )</td><td>-3119 ( 3119 )</td></tr><tr><td>4</td><td>dividends paid</td><td>-1333 ( 1333 )</td><td>-1146 ( 1146 )</td><td>-837 ( 837 )</td></tr><tr><td>5</td><td>free cash flow</td><td>$ 2085</td><td>$ 1382</td><td>$ 1917</td></tr></table> 2014 outlook f0b7 safety 2013 operating a safe railroad benefits our employees , our customers , our shareholders , and the communities we serve . we will continue using a multi-faceted approach to safety , utilizing technology , risk assessment , quality control , training and employee engagement , and targeted capital investments . we will continue using and expanding the deployment of total safety culture and courage to care throughout our operations , which allows us to identify and implement best practices for employee and operational safety . derailment prevention and the reduction of grade crossing incidents are also critical aspects of our safety programs . we will continue our efforts to increase detection of rail defects ; improve or close crossings ; and educate the public and law enforcement agencies about crossing safety through a combination of our own programs ( including risk assessment strategies ) , various industry programs and local community activities across our network . f0b7 network operations 2013 we believe the railroad is capable of handling growing volumes while providing high levels of customer service . our track structure is in excellent condition , and certain sections of our network have surplus line and terminal capacity . we are in a solid resource position , with sufficient supplies of locomotives , freight cars and crews to support growth . f0b7 fuel prices 2013 uncertainty about the economy makes projections of fuel prices difficult . we again could see volatile fuel prices during the year , as they are sensitive to global and u.s . domestic demand , refining capacity , geopolitical events , weather conditions and other factors . to reduce the impact of fuel price on earnings , we will continue seeking cost recovery from our customers through our fuel surcharge programs and expanding our fuel conservation efforts . f0b7 capital plan 2013 in 2014 , we plan to make total capital investments of approximately $ 3.9 billion , including expenditures for positive train control ( ptc ) , which may be revised if business conditions warrant or if new laws or regulations affect our ability to generate sufficient returns on these investments . ( see further discussion in this item 7 under liquidity and capital resources 2013 capital plan. ) f0b7 positive train control 2013 in response to a legislative mandate to implement ptc by the end of 2015 , we have invested $ 1.2 billion in capital expenditures and plan to spend an additional $ 450 million during 2014 on developing and deploying ptc . we currently estimate that ptc , in accordance with implementing rules issued by the federal rail administration ( fra ) , will cost us approximately $ 2 billion by the end of the project . this includes costs for installing the new system along our tracks , upgrading locomotives to work with the new system , and adding digital data communication equipment to integrate the various components of the system and achieve interoperability for the industry . although it is unlikely that the rail industry will meet the current mandatory 2015 deadline ( as the fra indicated in its 2012 report to congress ) , we are making a good faith effort to do so and we are working closely with regulators as we implement this new technology. .
Question: what is the sum of cash provided by operating activities in 2012 and 2013?
Answer: 12984.0
Question: what about the sum if 2011 is added to these two years?

user
18857.0
assistant