Page 1 of 92
WGU PUBH 6002 QUIZ 5 – 2026
BIOSTATISTICS PUBLIC HEALTH COMPLETE
(115) CURRENT TESTING QUESTIONS AND
CORRECT ANSWERS WITH DAETAILED
RATIONALES.
PUBH
Prepare for the WGU PubH 6002 Quiz 5 – Biostatistics Public Health with
focused review materials covering descriptive statistics, probability
concepts, sampling distributions, hypothesis testing, measures of central
tendency and variability, confidence intervals, and interpretation of
statistical findings in public health research. Designed to build
confidence in analyzing data, interpreting results, and making evidence-
based public health decisions. Suitable for WGU public health students
preparing for Quiz 3 in biostatistics and related examinations.
MULTIPLE CHOICE.
Domain 1: Probability & Distributions (Questions 1–25)
1. What is the probability of rolling a sum of 7 with two fair six-
sided dice?
A. 1/6
B. 1/12
C. 5/36
D. 6/36
Correct answer: D. 6/36
Rationale: There are 36 possible outcomes when rolling two dice.
, Page 2 of 92
The combinations that sum to 7 are (1,6), (2,5), (3,4), (4,3), (5,2), and
(6,1)—a total of 6 outcomes. Therefore, the probability is 6/36,
which simplifies to 1/6.
2. A public health researcher is studying the prevalence of
hypertension in a population. The prevalence is 25%. If the
researcher selects 4 individuals at random, what is the
probability that exactly 2 have hypertension?
A. 0.0469
B. 0.2109
C. 0.3164
D. 0.4219
Correct answer: B. 0.2109
Rationale: This is a binomial probability problem: n=4, p=0.25, x=2.
Using the formula P(X=x) = C(n,x) * p^x * (1-p)^(n-x) = 6 * (0.25)^2 *
(0.75)^2 = 6 * 0.0625 * 0.5625 = 0.2109.
3. The standard normal distribution has a mean of _____ and a
standard deviation of _____:
A. 0, 1
B. 1, 0
C. 50, 10
D. 100, 15
Correct answer: A. 0, 1
Rationale: The standard normal distribution is a special case of the
normal distribution with a mean of 0 and a standard deviation of 1. It
is used to calculate z-scores and probabilities.
4. A study reports that the mean BMI of a population is 28.5 with
a standard deviation of 4.2. If BMI is normally distributed, what is
, Page 3 of 92
the z-score for an individual with a BMI of 32.0?
A. -0.83
B. 0.83
C. 1.67
D. -1.67
Correct answer: B. 0.83
Rationale: The z-score is calculated as z = (x - μ) / σ = (32.0 - 28.5) /
4.2 = 3..2 = 0.8333, which rounds to 0.83. This indicates the
individual's BMI is 0.83 standard deviations above the mean.
5. In a normal distribution, approximately what percentage of
observations fall within ±2 standard deviations of the mean?
A. 68%
B. 90%
C. 95%
D. 99.7%
Correct answer: C. 95%
Rationale: The empirical rule states that approximately 68% of data
falls within ±1 standard deviation, 95% within ±2 standard
deviations, and 99.7% within ±3 standard deviations of the mean in
a normal distribution.
6. Which of the following is a characteristic of the binomial
distribution?
A. It is used for continuous data
B. It has two possible outcomes (success/failure)
C. It is always symmetrical
D. It has no fixed number of trials
Correct answer: B. It has two possible outcomes
(success/failure)
, Page 4 of 92
Rationale: The binomial distribution models the number of
successes in a fixed number of independent trials, each with two
possible outcomes (success or failure).
7. The probability of an event A occurring given that event B has
already occurred is known as:
A. Marginal probability
B. Joint probability
C. Conditional probability
D. Independent probability
Correct answer: C. Conditional probability
Rationale: Conditional probability is the probability of event A
occurring given that event B has occurred, denoted as P(A|B).
8. Two events are independent if:
A. P(A and B) = P(A) × P(B)
B. P(A and B) = P(A) + P(B)
C. P(A and B) = 0
D. P(A|B) = 0
Correct answer: A. P(A and B) = P(A) × P(B)
Rationale: Two events are independent if the occurrence of one
does not affect the probability of the other. Mathematically, this is
expressed as P(A and B) = P(A) × P(B).
9. In a Poisson distribution, the mean and variance are:
A. Equal
B. Unequal
C. Mean is greater than variance
D. Variance is greater than mean
Correct answer: A. Equal
WGU PUBH 6002 QUIZ 5 – 2026
BIOSTATISTICS PUBLIC HEALTH COMPLETE
(115) CURRENT TESTING QUESTIONS AND
CORRECT ANSWERS WITH DAETAILED
RATIONALES.
PUBH
Prepare for the WGU PubH 6002 Quiz 5 – Biostatistics Public Health with
focused review materials covering descriptive statistics, probability
concepts, sampling distributions, hypothesis testing, measures of central
tendency and variability, confidence intervals, and interpretation of
statistical findings in public health research. Designed to build
confidence in analyzing data, interpreting results, and making evidence-
based public health decisions. Suitable for WGU public health students
preparing for Quiz 3 in biostatistics and related examinations.
MULTIPLE CHOICE.
Domain 1: Probability & Distributions (Questions 1–25)
1. What is the probability of rolling a sum of 7 with two fair six-
sided dice?
A. 1/6
B. 1/12
C. 5/36
D. 6/36
Correct answer: D. 6/36
Rationale: There are 36 possible outcomes when rolling two dice.
, Page 2 of 92
The combinations that sum to 7 are (1,6), (2,5), (3,4), (4,3), (5,2), and
(6,1)—a total of 6 outcomes. Therefore, the probability is 6/36,
which simplifies to 1/6.
2. A public health researcher is studying the prevalence of
hypertension in a population. The prevalence is 25%. If the
researcher selects 4 individuals at random, what is the
probability that exactly 2 have hypertension?
A. 0.0469
B. 0.2109
C. 0.3164
D. 0.4219
Correct answer: B. 0.2109
Rationale: This is a binomial probability problem: n=4, p=0.25, x=2.
Using the formula P(X=x) = C(n,x) * p^x * (1-p)^(n-x) = 6 * (0.25)^2 *
(0.75)^2 = 6 * 0.0625 * 0.5625 = 0.2109.
3. The standard normal distribution has a mean of _____ and a
standard deviation of _____:
A. 0, 1
B. 1, 0
C. 50, 10
D. 100, 15
Correct answer: A. 0, 1
Rationale: The standard normal distribution is a special case of the
normal distribution with a mean of 0 and a standard deviation of 1. It
is used to calculate z-scores and probabilities.
4. A study reports that the mean BMI of a population is 28.5 with
a standard deviation of 4.2. If BMI is normally distributed, what is
, Page 3 of 92
the z-score for an individual with a BMI of 32.0?
A. -0.83
B. 0.83
C. 1.67
D. -1.67
Correct answer: B. 0.83
Rationale: The z-score is calculated as z = (x - μ) / σ = (32.0 - 28.5) /
4.2 = 3..2 = 0.8333, which rounds to 0.83. This indicates the
individual's BMI is 0.83 standard deviations above the mean.
5. In a normal distribution, approximately what percentage of
observations fall within ±2 standard deviations of the mean?
A. 68%
B. 90%
C. 95%
D. 99.7%
Correct answer: C. 95%
Rationale: The empirical rule states that approximately 68% of data
falls within ±1 standard deviation, 95% within ±2 standard
deviations, and 99.7% within ±3 standard deviations of the mean in
a normal distribution.
6. Which of the following is a characteristic of the binomial
distribution?
A. It is used for continuous data
B. It has two possible outcomes (success/failure)
C. It is always symmetrical
D. It has no fixed number of trials
Correct answer: B. It has two possible outcomes
(success/failure)
, Page 4 of 92
Rationale: The binomial distribution models the number of
successes in a fixed number of independent trials, each with two
possible outcomes (success or failure).
7. The probability of an event A occurring given that event B has
already occurred is known as:
A. Marginal probability
B. Joint probability
C. Conditional probability
D. Independent probability
Correct answer: C. Conditional probability
Rationale: Conditional probability is the probability of event A
occurring given that event B has occurred, denoted as P(A|B).
8. Two events are independent if:
A. P(A and B) = P(A) × P(B)
B. P(A and B) = P(A) + P(B)
C. P(A and B) = 0
D. P(A|B) = 0
Correct answer: A. P(A and B) = P(A) × P(B)
Rationale: Two events are independent if the occurrence of one
does not affect the probability of the other. Mathematically, this is
expressed as P(A and B) = P(A) × P(B).
9. In a Poisson distribution, the mean and variance are:
A. Equal
B. Unequal
C. Mean is greater than variance
D. Variance is greater than mean
Correct answer: A. Equal
