Question: According to the U.S. National Science Foundation, the distribution of graduate science students in doctorate-granting institutions is as follows (frequencies are in thousands):

Field Frequency

Physical sciences 31.3

Environmental 13.1

Mathematical sciences 16.4

Computer sciences 47.6

Agricultural sciences 11.8

Biological sciences 57.2

Psychology 40.8

Social sciences 78.8

A graduate science student who is attending a doctorate-granting institution is selected at random. Determine the probability that the field of the student obtained is:

(a) psychology

(b) physical or social science

(c) not computer science