9. In the expansion of the binomial $( x + 1 ) ^ { 10 }$, if a term is chosen at random, the probability that the coefficient of that term is odd is $\_\_\_\_$. (Express the result as a fraction)
9. In the expansion of the binomial $( x + 1 ) ^ { 10 }$, if a term is chosen at random, the probability that the coefficient of that term is odd is $\_\_\_\_$. (Express the result as a fraction)