Answer
$P(\text{not mathematics}) = 0.969$
If we select 1000 doctoral degrees from U.S. universities in 2009, we would expect about 969 of them not to be mathematics.
Work Step by Step
The event: "candidate who earned a degree in 2009 did not study mathematics" is the complement of "candidate who earned a degree in 2009 studied mathematics."
$P(\text{not mathematics}) = 1 - P(\text{mathematics}) = 1-0.031=0.969.$
