AVERAGE RETURN: ????

What is the value for cell B26? B26 calculates the arithmetic mean stock return from Jan 2017 to June 2017 (Show in decimals and round to four decimal points. ex. 0.1234) D E 23 Ticker 6/30/2017 5/31/2017 4/30/2017 3/31/2017 2/28/2017 1/31/2017 24 ORCL 50.14 45.39 44.96 44.61 25 Relative Return 4.74% 6.18% 26 Average Return 42.59 40.11 0.96% 10.46% ? 0.78%