A study reported in February 2008 that an Australian dermatologist established a link between alcoholism/drug addiction and gray hair in people in their early thirties, with results as shown in this table.
a. Was this an observational study or an experiment?
b. For the people in this study, find the probability of having gray hair, P(G), and the probability of being addicted to drugs or alcohol, P(A).
c. How many people had gray hair and were addicted to drugs or alcohol?
d. What was the probability of having gray hair and being addicted to drugs or alcohol?
e. Show that the product P(G)P(A) does not equal P(G and A).
f. Does suffering from alcoholism/drug addiction have an impact on the probability of having gray hair?