QUESTION 1

1. In a sample of 2,000 drivers, 860 had their seat belts fastened. If one driver is

chosen at random, the probability that the driver chosen was not using a seat belt is

A..14

B..43

C..57

D..86

E..95

QUESTION 2

1. Assume a cardiovascular surgeon has implanted 13 pacemakers in his patients from a new batch of pacemakers that have been found to have a defect that causes them to stop working. If each pacemaker has a 23.47% chance that it will stop working, what is the probability that all the patients' pacemakers will work the way they are supposed to?

A..4730

B.6.5565E-09

C..0309

D..0527

2 points

QUESTION 3

1. A recent study on teenage pregnancy indicates that 10% of a very large female population will get pregnant sometime in their teenage years. The study stated that teenage pregnancies occur independently of one another. Suppose 6 teenage women were randomly selected. Find the probability that none of these women will get pregnant some time in their teenage years.

A..5314

B..9672

C..2036

D..2262

E..7351

QUESTION 4

1. Assume a researcher wanted to know the probability that an individual's systolic blood pressure would fall below 157 and the researcher found that the z-score corresponding to the 157 systolic blood pressure is 1.62. What is the probability that a random individual's systolic blood pressure would fall below 157 if the probability distribution of systolic blood pressure is normal?

A..4740

B..9474

C..5260

D..0526

2 points

QUESTION 5

1. Suppose that the mean and the standard deviation of weight of certain ethnic group of people that are five foot tall are: mean = 130 and standard deviation = 15. If we assume that the distribution of weight is normally distributed, what is the 90-th percentile in the weight distribution of this ethnic group of people? (Select one value below that is the closest to the answer.)

A.132.76

B.133.75

C.149.20

D.145.00

E.160.00

2 points

QUESTION 6

1. Assuming you obtained a random sample of blood glucose levels from 32 individuals from a population and the mean of the population is 120 and the standard deviation of the sample is 15, calculate the probability that the mean blood glucose levels for the sample population will be above 127.

A. .5900 B. .9959 C. .4100 D. .0041

3 points

QUESTION 10

It is reported in a study that the sensitivity of a mammogram as a screening test

for detecting a breast cancer is 90%, and the specificity is 80%. The prevalence

of the breast cancer is estimated to be 8%. What is the predictive value of a

positive test? (Or say, if a person is tested positive, what is the probability that

this person has breast cancer?)

A..98

B..28

C..82

D..09