Answer
$\dfrac{293}{3700}$
Work Step by Step
Let us consider that $A$ denotes sale took place outside west and $B$ denotes sale took place in the month of the February 2011 .
Thus, we can find the probability as:
$P(B \ | A)=\dfrac{293000}{(4.9-1.2)\times 10^6}=\dfrac{293}{3700}$