The following probability model shows the distribution of doctoral degrees from U.S. universities in 2009 by area of study:
Area of study Probability
Engineering 0.154
Physical sciences 0.087
Life sciences 0.203
Mathematics 0.031
Computer sciences 0.033
Social sciences 0.168
Humanities 0.094
Education 0.132
Professional & other fields 0.056
Health 0.042
A- Verify that this is a probability model.
B- What is the probability that a randomly sselected doctoral candidate who earned a degree in 2009 studied physical science or life science. Interpret this probability.
C- What is the probability that a randomly selected doctoral candidate who earned a degree in 2009 studied physical science, life science, mathematics or computer science? Interpret this probability.
D- What is the probability that a randomly selected doctoral candidate who earned a degree in 2009 did not study mathematics? Interpret this probabiity.