Answer Happy

Use the following prompt to answer the AGGRESSION questions. Psychologists tend to believe that there is a relationship between aggressive behavior and order to birth. To test this belief, a psychologist chose 500 elementary school students at random and administered each a test designed to measure the student's aggressiveness. Each student was classified according to one of four categories. The numbers of students falling in the four categories are shown here. First-born Not first-born 80 65 Aggressive Not aggressive 160 195
Are the events that a chosen student is aggressive and that a chosen student is first-born independent? Explain your answer.
AGGRESSION What is the probability that the student is aggressive, given that the student was not first-born?
What is the probability that a randomly chosen student is not aggressive OR the student is first-born.