In a study on the effect of maternal exposure to cigarettes on the risk of preterm birth, the number of preterm births occurring among 130 women who smoked during pregnancy between 2010 and 2012 was compared to the number of preterm births among 192 women who did not smoke during pregnancy during the same time period. In a second study, the pregnancy medical records of 55 women who gave birth to premature infants were compared to those of 98 women who did not have a premature infant in order to assess if the women smoked during pregnancy.Which of the following statements is correct?

A graduate student is registering for 3 courses in one semester. X=the number of courses that are full at the time of registration.  The random variable X has a probability distribution as follows x 0 1 2 3 p(x) 0.45 0.25 0.20 0.10 The probability that more than two of the classes are full at the time of registration P(X >2) is equal to

Four hundred women are enrolled in a study to evaluate the accuracy of a test for pregnancy. 200 of the women were actually pregnant. 170 of the pregnant women had a positive test as did 40 of the women who were not pregnant. What is the probability (i.e., PPV) that a woman is pregnant given that she tested positive on a screening test? Test                         Pregnant? Yes No Total + 170 40 210 – 30 160 190 Total 200 200 400

Select statement below that is true about correlations.

A graduate student is registering for 3 courses in one semester. X=the number of courses that are full at the time of registration.  The random variable X has a probability distribution as follows x 0 1 2 3 p(x) 0.55 0.25 0.15 0.05 The probability that less than one of the classes are full at the time of registration is equal to

For a sampling distribution for proportions you can assume it follows a normal distribution if p-hat times sample size and 1-phat times sample size are both greater than ten.

Select the term that best fits this definition: A range of values that capture the true population value with a specified level of confidence

A graduate student is registering for 3 courses in one semester. X=the number of courses that are full at the time of registration.  The random variable X has a probability distribution as follows x 0 1 2 3 p(x) 0.55 0.25 0.15 0.05 The probability that one or fewer of the classes are full at the time of registration [P(X

Select the correct definition of p-value

4 students apply to a PhD program. The program accepts 70% of all applicants. Students are accepted and rejected independently of each other. Let the random variable X represent the number out of the 4 students who get accepted from the PhD Program. (Hint: Binomial distribution with n=4 and p=70%)   What is the mean of the random variable? (round your answer to 4 decimal places)