4,331 women were studied by researchers at Mayo Clinic with the results shown in the table below. (Source: Michael Weitzman, Steven Gortmaker, Deborah Klein Walker, and Arthur Sobol, “Maternal Smoking and Childhood Asthma,” Pediatrics, Vol. 85, No. 4, April 1990)
Mother’s Education Smoked Didn’t Smoke Row Total
Below high school 393 640 1,033
High School 560 1,370 1,930
Some College 121 635 756
College Degree 48 550 598
Col Total 1,122 3,209 4,331
27. What is the probability that a mother in the study smoked during pregnancy?
28. What is the probability that a mother smoked during pregnancy if her education level is below high school?
29. What is the probability that a mother smoked during pregnancy and had a college degree?
30. What is the probability that a mother smoked during pregnancy or that she graduated from college?
31. If a mother attended college, what is the probability that she did not smoke during her pregnancy?
32. Is smoking during pregnancy independent of education?
33. Debbie has two stocks, X and Y. Consider the following events:
X = the event that the price of stock X has increased
Y = the event that the price of stock Y has increased
The event “the price of stock X has increased and the price of stock Y has not increased” may be written as
34. In a certain sample space, the following probabilities are given:
P(AB) = 0.40
P(B) = 0.30
P(BA) = 0.70
P(A B) is equal to
