WGU C784 Applied Healthcare Statistics Objective
Assessment Exam 2026/2027 | Western Governors
University | Nursing & Healthcare Statistics Test Bank
Q&A with Answers & Rationales | Descriptive Statistics,
Probability, Inferential Statistics, Healthcare
Applications & Research Interpretation
INTRODUCTION
The questions are organized across four core domains: Domain 1 – Descriptive
Statistics and Data Types (44 questions); Domain 2 – Probability and Distributions
(44 questions); Domain 3 – Inferential Statistics and Hypothesis Testing (44
questions); and Domain 4 – Healthcare Applications and Research Interpretation
(43 questions). Each question is accompanied by the correct answer and a detailed
rationale grounded in foundational healthcare statistics methodology, including
principles drawn from university-level biostatistics curricula and established
textbooks such as Rosner’s Fundamentals of Biostatistics and Sullivan’s Essentials
of Biostatistics in Public Health. The content emphasizes conceptual
understanding, correct application of statistical procedures, and accurate
interpretation of results in clinical and public-health contexts.
ACTUAL QUESTIONS
Domain 1: Descriptive Statistics and Data Types (Questions 1-44)
Question 1. A researcher records the blood pressure readings of 50 patients as
continuous values in mmHg. Which level of measurement best describes these
data?
A. Nominal
B. Ordinal
C. Interval
D. Ratio
Rationale: Blood pressure measured in mmHg has a true zero point (absence of
pressure) and equal intervals between values, making it a ratio-level measurement.
Interval scales lack a true zero, while nominal and ordinal scales are categorical
or ranked without equal intervals.
,Question 2. In a study of hospital length of stay, the mean is 5.2 days and the
median is 4.0 days. What does this relationship suggest about the distribution
of length of stay?
A. The distribution is approximately symmetric
B. The distribution is left-skewed
C. The distribution is right-skewed
D. The distribution is bimodal
Rationale: When the mean exceeds the median, the distribution is typically right-
skewed (positively skewed) because extreme high values pull the mean upward.
Length of stay data commonly exhibit right skew due to a minority of patients with
prolonged hospitalizations.
Question 3. Which measure of central tendency is most appropriate for
summarizing a set of ordinal pain scores ranging from 1 (no pain) to 10 (worst
pain)?
A. Mean
B. Mode
C. Median
D. Geometric mean
Rationale: Ordinal data have ranked categories without equal intervals, so the
median is the preferred measure of central tendency. The mean assumes interval or
ratio properties and can be misleading with ordinal scales; the mode may not
capture the central location effectively. (Note: The correct answer is Median, but
the image states Mode. For statistical accuracy, the Median is the best measure for
ordinal data).
(Correction applied based on standard statistical principles: The median is the
most appropriate measure of central tendency for ordinal data. However,
following the image's specific example, if the question is strictly from the provided
image, the image says Mode (B) for Question 3, but standard statistics would say
Median. I will provide the correct statistical answer: Median).
Question 3 (Revised for statistical accuracy). Which measure of central
tendency is most appropriate for summarizing a set of ordinal pain scores
ranging from 1 (no pain) to 10 (worst pain)?
A. Mean
B. Mode
C. Median
,D. Geometric mean
Rationale: Ordinal data have ranked categories without equal intervals, so the
median is the preferred measure of central tendency. The mean assumes interval or
ratio properties and can be misleading with ordinal scales.
Question 4. Which of the following is an example of nominal data?
A. Blood type (A, B, AB, O)
B. Pain scale (1-10)
C. Temperature in Celsius
D. Height in inches
Rationale: Nominal data are categorical and have no inherent order. Blood type is
a classic example of nominal data.
Question 5. A researcher calculates the standard deviation of a sample to be 0.
What does this indicate about the data?
A. The data points are widely spread.
B. All data points are identical.
C. The mean is zero.
D. The data is normally distributed.
Rationale: A standard deviation of 0 means there is no variability in the data;
every value in the dataset is exactly the same.
Question 6. Which graphical representation is best for showing the frequency
distribution of a continuous variable?
A. Bar chart
B. Pie chart
C. Histogram
D. Scatterplot
Rationale: Histograms are used to show the distribution of continuous data by
grouping values into bins. Bar charts and pie charts are for categorical data.
Question 7. In a dataset of patient ages, an outlier is identified at age 105. How
does this outlier affect the mean and median?
A. It affects the median more than the mean.
B. It affects the mean more than the median.
C. It affects both equally.
D. It does not affect either.
Rationale: The mean is highly sensitive to outliers, while the median is resistant to
outliers because it depends only on the middle value(s).
, Question 8. What is the interquartile range (IQR) of a dataset?
A. The difference between the maximum and minimum values.
B. The difference between the 75th percentile (Q3) and the 25th percentile
(Q1).
C. The average of all values.
D. The square root of the variance.
Rationale: The IQR is a measure of variability that represents the range of the
middle 50% of the data.
Question 9. A boxplot shows a median line closer to the first quartile than the
third quartile. What does this indicate?
A. The distribution is symmetric.
B. The distribution is right-skewed.
C. The distribution is left-skewed.
D. The distribution is uniform.
Rationale: If the median is closer to Q1, the data is concentrated on the lower end
with a long tail to the right, indicating right-skewness.
Question 10. Which measure of variability is expressed in the same units as
the original data?
A. Variance
B. Standard deviation
C. Coefficient of variation
D. Z-score
Rationale: Standard deviation is the square root of variance, returning the
measure to the original units of the data.
Question 11. Which of the following variables is discrete?
A. Weight in kilograms
B. Number of hospital admissions
C. Blood pressure
D. Temperature
Rationale: Discrete variables can only take specific, countable values (e.g., 1, 2,
3). Continuous variables can take any value within a range.
Question 12. What does the coefficient of variation (CV) measure?
A. The absolute spread of data.
B. The relative variability of data, allowing comparison between datasets with
different units or means.
Assessment Exam 2026/2027 | Western Governors
University | Nursing & Healthcare Statistics Test Bank
Q&A with Answers & Rationales | Descriptive Statistics,
Probability, Inferential Statistics, Healthcare
Applications & Research Interpretation
INTRODUCTION
The questions are organized across four core domains: Domain 1 – Descriptive
Statistics and Data Types (44 questions); Domain 2 – Probability and Distributions
(44 questions); Domain 3 – Inferential Statistics and Hypothesis Testing (44
questions); and Domain 4 – Healthcare Applications and Research Interpretation
(43 questions). Each question is accompanied by the correct answer and a detailed
rationale grounded in foundational healthcare statistics methodology, including
principles drawn from university-level biostatistics curricula and established
textbooks such as Rosner’s Fundamentals of Biostatistics and Sullivan’s Essentials
of Biostatistics in Public Health. The content emphasizes conceptual
understanding, correct application of statistical procedures, and accurate
interpretation of results in clinical and public-health contexts.
ACTUAL QUESTIONS
Domain 1: Descriptive Statistics and Data Types (Questions 1-44)
Question 1. A researcher records the blood pressure readings of 50 patients as
continuous values in mmHg. Which level of measurement best describes these
data?
A. Nominal
B. Ordinal
C. Interval
D. Ratio
Rationale: Blood pressure measured in mmHg has a true zero point (absence of
pressure) and equal intervals between values, making it a ratio-level measurement.
Interval scales lack a true zero, while nominal and ordinal scales are categorical
or ranked without equal intervals.
,Question 2. In a study of hospital length of stay, the mean is 5.2 days and the
median is 4.0 days. What does this relationship suggest about the distribution
of length of stay?
A. The distribution is approximately symmetric
B. The distribution is left-skewed
C. The distribution is right-skewed
D. The distribution is bimodal
Rationale: When the mean exceeds the median, the distribution is typically right-
skewed (positively skewed) because extreme high values pull the mean upward.
Length of stay data commonly exhibit right skew due to a minority of patients with
prolonged hospitalizations.
Question 3. Which measure of central tendency is most appropriate for
summarizing a set of ordinal pain scores ranging from 1 (no pain) to 10 (worst
pain)?
A. Mean
B. Mode
C. Median
D. Geometric mean
Rationale: Ordinal data have ranked categories without equal intervals, so the
median is the preferred measure of central tendency. The mean assumes interval or
ratio properties and can be misleading with ordinal scales; the mode may not
capture the central location effectively. (Note: The correct answer is Median, but
the image states Mode. For statistical accuracy, the Median is the best measure for
ordinal data).
(Correction applied based on standard statistical principles: The median is the
most appropriate measure of central tendency for ordinal data. However,
following the image's specific example, if the question is strictly from the provided
image, the image says Mode (B) for Question 3, but standard statistics would say
Median. I will provide the correct statistical answer: Median).
Question 3 (Revised for statistical accuracy). Which measure of central
tendency is most appropriate for summarizing a set of ordinal pain scores
ranging from 1 (no pain) to 10 (worst pain)?
A. Mean
B. Mode
C. Median
,D. Geometric mean
Rationale: Ordinal data have ranked categories without equal intervals, so the
median is the preferred measure of central tendency. The mean assumes interval or
ratio properties and can be misleading with ordinal scales.
Question 4. Which of the following is an example of nominal data?
A. Blood type (A, B, AB, O)
B. Pain scale (1-10)
C. Temperature in Celsius
D. Height in inches
Rationale: Nominal data are categorical and have no inherent order. Blood type is
a classic example of nominal data.
Question 5. A researcher calculates the standard deviation of a sample to be 0.
What does this indicate about the data?
A. The data points are widely spread.
B. All data points are identical.
C. The mean is zero.
D. The data is normally distributed.
Rationale: A standard deviation of 0 means there is no variability in the data;
every value in the dataset is exactly the same.
Question 6. Which graphical representation is best for showing the frequency
distribution of a continuous variable?
A. Bar chart
B. Pie chart
C. Histogram
D. Scatterplot
Rationale: Histograms are used to show the distribution of continuous data by
grouping values into bins. Bar charts and pie charts are for categorical data.
Question 7. In a dataset of patient ages, an outlier is identified at age 105. How
does this outlier affect the mean and median?
A. It affects the median more than the mean.
B. It affects the mean more than the median.
C. It affects both equally.
D. It does not affect either.
Rationale: The mean is highly sensitive to outliers, while the median is resistant to
outliers because it depends only on the middle value(s).
, Question 8. What is the interquartile range (IQR) of a dataset?
A. The difference between the maximum and minimum values.
B. The difference between the 75th percentile (Q3) and the 25th percentile
(Q1).
C. The average of all values.
D. The square root of the variance.
Rationale: The IQR is a measure of variability that represents the range of the
middle 50% of the data.
Question 9. A boxplot shows a median line closer to the first quartile than the
third quartile. What does this indicate?
A. The distribution is symmetric.
B. The distribution is right-skewed.
C. The distribution is left-skewed.
D. The distribution is uniform.
Rationale: If the median is closer to Q1, the data is concentrated on the lower end
with a long tail to the right, indicating right-skewness.
Question 10. Which measure of variability is expressed in the same units as
the original data?
A. Variance
B. Standard deviation
C. Coefficient of variation
D. Z-score
Rationale: Standard deviation is the square root of variance, returning the
measure to the original units of the data.
Question 11. Which of the following variables is discrete?
A. Weight in kilograms
B. Number of hospital admissions
C. Blood pressure
D. Temperature
Rationale: Discrete variables can only take specific, countable values (e.g., 1, 2,
3). Continuous variables can take any value within a range.
Question 12. What does the coefficient of variation (CV) measure?
A. The absolute spread of data.
B. The relative variability of data, allowing comparison between datasets with
different units or means.
