Graduate Science Students. According to Survey of Graduate Science Engineering Students and Postdoctorates, published by the U.S. National Science Foundation, the distribution of graduate science students in doctorate-granting institutions is as follows. Frequencies are in thousands. Note: Earth sciences include atmospheric and ocean sciences as well.

Field Frequency Agricultural sciences 15.1 Biological sciences 69.7 Computer sciences 46.1 Earth sciences 14.9 Mathematical sciences 22.0 Physical sciences 38.7 Psychology 45.6 Social sciences 97.2 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.