Answer
$P(\text{physical science or life science or mathematics or computer science}) = 0.354$
If we select 1000 doctoral degrees from U.S. universities in 2009, we would expect about 354 to be physical science, life science, mathematics, or computer science.
Work Step by Step
$P(\text{physical science or life science or mathematics or computer science}) = P(\text{physical science}) + P(\text{life science}) + P(\text{mathematics}) + P(\text{computer science}) = 0.087+0.203+0.031+0.033 = 0.354.$
This is the Addition Rule for Disjoint Events.
