According to asurvey, the distribution of graduate science students indoctorate-granting institutions is shown to the right. Frequencies are in thousands. A graduate science student who is attending adoctorate-granting institution is selected at random. Complete parts a through c.

Field frequency

physical sciences 35.7

Environmental sciences 11.5

Mathematical sciences 17.1

computers sciences 44.1

Agricultural sciences 12.7

Biological sciences 63.1

Psychology 46.6

social sciences 88.4

a. Determine the probability that the field of the student obtained is psychology.

b=

c=