Chapter 05

Multiple Choice

1. Assuming the below results were obtained in a study used to test the accuracy of the rapid diagnostic test for influenza, calculate and interpret the sensitivity of the rapid diagnostic influenza test.

A) When the rapid diagnostic influenza test is used, 52.22% of individuals who have the flu test positive for the flu.

B) When the rapid diagnostic influenza test is used, 90.91% of individuals who have the flu test positive for the.

C) When the rapid diagnostic influenza test is used, 47.78% of individuals who have the flu test positive for the flu.

D) When the rapid diagnostic influenza test is used, 9.09% of individuals who have the flu test positive for the flu.

2. 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 work, what is the probability that all the patients’ pacemakers will work the way they are supposed to?

A) 6.556e-9

B) .0527

C) .4730

D) .5270

3. 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) .0041

B) .4100

C) .5900

D) .9959

4. As part of the study described in Problem 6, investigators wanted to assess the accuracy of self-reported smoking status. Participants are asked whether they currently smoke or not. In addition, laboratory tests are performed on hair samples to determine presence or absence of nicotine. The laboratory assessment is considered the gold standard, or truth about nicotine consumption. The data are as follows:

What is the specificity of self-reported smoking status?

A)1

B)0.1

C)0.84

D)0.90

5. Diastolic blood pressures are assumed to follow a normal distribution with a mean of 85 and a standard deviation of 12. What proportion of people has diastolic blood pressures less than 80?

A)0.661

B)0.338

C)0.50

D)0.75

6. The following table cross-classifies pregnant women in the study by their body mass index (BMI) at 16 weeks gestation and whether they had pre-term delivery. What is the probability of women with BMI less than 30 and delivers pre-term?

A)0.0867

B)0.2857

C)0.0533

D)0.533

7. The following table cross-classifies pregnant women in the study by their body mass index (BMI) at 16 weeks gestation and whether they had pre-term delivery. What proportion of women with BMI greater than 35 delivers pre-term?

A)0.0867

B)0.2857

C)0.0533

D)0.533

8. High density lipoprotein (HDL) in healthy males follows a normal distribution with a mean of 50 and a standard deviation of 8. What proportion of healthy males has HDL exceeding 60? 

A)0.50

B)1.00

C)0.894

D)0.106

9. An experimental drug has been shown to be 75% effective in eliminating symptoms of allergies in animal studies. A small human study involving six participants is conducted. What is the probability that the drug is effective on half of the participants?

A)0.132

B)0.868

C)0.50

D)0.20

10. A national survey of graduate students is conducted to assess their consumption of coffee. The following table summarizes the data. What proportion of coffee drinkers (caffeinated and decaffeinated) is female?

A)0.70

B)0.50

C)0.90

D)0.546

True/False

11. True or False? In stratified sampling, the population is split into non-overlapping groups or strata (e.g., men and women; people under 30 years of age and people 30 years of age and older) and then sample within each strata.

12. True or False? Sensitivity and specificity are both forms of conditional probability.

13. True or False? In Simple random sampling, each member of the population is assigned a unique identification number, and then a set of numbers is selected at random to determine the individuals to be included in the sample.

14. True or False? A percentile is a value in the distribution that holds a specified percentage of the population below it.

15. True or False? The normal distribution model is an important probability distribution model that is appropriate when a particular experiment or process results in a continuous outcome.