WGU C784 Applied Healthcare Statistics
Objective Assessment 1 (2025–2026) |
Comprehensive Study Guide, Practice
Questions & Verified Answers for OA Exam
Prep
WGU C784 Applied Healthcare Statistics Objective Assessment 1 (2025–2026)
Comprehensive Study Guide & Practice Exam
DOCUMENT OVERVIEW:
• This comprehensive practice exam contains 200 carefully constructed multiple-
choice questions designed to simulate the actual WGU C784 OA1 assessment,
covering all major statistical concepts, applications, and healthcare-specific
scenarios you'll encounter on exam day.
• Use this material by working through questions systematically, reviewing
rationales for both correct and incorrect answers to strengthen conceptual
understanding, then retaking challenging sections to build mastery before
attempting the official assessment.
QUESTION 1
A research team is analyzing patient wait times at a clinic. The recorded wait
times (in minutes) for 10 patients are: 15, 22, 18, 25, 20, 15, 30, 18, 22, and 28.
What is the median wait time?
A) 20 minutes
B) 21 minutes
C) 22 minutes
D) 23 minutes
,E) 24 minutes
CORRECT ANSWER: B) 21 minutes
Rationale: To find the median, arrange the data in order: 15, 15, 18, 18, 20, 22, 22,
25, 28, 30. With 10 values (even number), the median is the average of the 5th and
6th values: (20 + 22) ÷ 2 = 21 minutes. The median is the middle value(s) in an
ordered dataset and is less affected by outliers than the mean.
QUESTION 2
A healthcare provider wants to understand the variation in patient
satisfaction scores across three different departments. Which measure would
best describe the spread of scores within each department?
A) The range only
B) The mode exclusively
C) Standard deviation and variance
D) The median alone
E) The interquartile range only
CORRECT ANSWER: C) Standard deviation and variance
Rationale: Standard deviation and variance are the most comprehensive measures
of spread, showing how individual scores deviate from the mean. While range and
interquartile range show spread, standard deviation and variance are more
sensitive to all data points and are more appropriate for comparing variation across
groups in statistical analysis and quality improvement initiatives.
QUESTION 3
In a normally distributed population of patient blood pressure readings, the
mean is 120 mmHg and the standard deviation is 10 mmHg. Approximately
what percentage of readings fall between 110 and 130 mmHg?
,A) 34%
B) 68%
C) 95%
D) 99.7%
E) 50%
CORRECT ANSWER: B) 68%
Rationale: According to the empirical rule (68-95-99.7 rule) for normal
distributions, approximately 68% of data falls within one standard deviation of the
mean. The range 110–130 mmHg represents mean ± 1 SD (120 ± 10), which
encompasses approximately 68% of the population in a normal distribution.
QUESTION 4
A hospital conducts a study to compare recovery times between two
treatment groups. Which statistical test would be most appropriate for
comparing the means of two independent groups?
A) Chi-square test
B) Independent samples t-test
C) Paired t-test
D) ANOVA
E) Correlation analysis
CORRECT ANSWER: B) Independent samples t-test
Rationale: An independent samples t-test is designed to compare the means of
two independent groups and determine if the difference is statistically significant.
Chi-square tests categorical data, paired t-tests compare dependent/matched
samples, ANOVA compares three or more groups, and correlation examines
relationships between variables, not group mean differences.
, QUESTION 5
A researcher collects data on patient age, collected as: <18, 18–30, 31–45, 46–
65, >65. What type of data measurement scale is this?
A) Nominal
B) Ordinal
C) Interval
D) Ratio
E) Continuous
CORRECT ANSWER: B) Ordinal
Rationale: Ordinal data has a natural order or ranking (age groups progress from
youngest to oldest) but the intervals between categories are not equal. Nominal
data has no order, interval data has equal intervals with no true zero, ratio data has
equal intervals with a true zero, and continuous data takes any value within a
range.
QUESTION 6
A healthcare facility wants to estimate the proportion of patients who
experience adverse events. A sample of 500 patients shows 45 adverse events.
What is the point estimate for the proportion?
A) 0.05
B) 0.09
C) 0.15
D) 0.20
E) 0.25
CORRECT ANSWER: B) 0.09
Objective Assessment 1 (2025–2026) |
Comprehensive Study Guide, Practice
Questions & Verified Answers for OA Exam
Prep
WGU C784 Applied Healthcare Statistics Objective Assessment 1 (2025–2026)
Comprehensive Study Guide & Practice Exam
DOCUMENT OVERVIEW:
• This comprehensive practice exam contains 200 carefully constructed multiple-
choice questions designed to simulate the actual WGU C784 OA1 assessment,
covering all major statistical concepts, applications, and healthcare-specific
scenarios you'll encounter on exam day.
• Use this material by working through questions systematically, reviewing
rationales for both correct and incorrect answers to strengthen conceptual
understanding, then retaking challenging sections to build mastery before
attempting the official assessment.
QUESTION 1
A research team is analyzing patient wait times at a clinic. The recorded wait
times (in minutes) for 10 patients are: 15, 22, 18, 25, 20, 15, 30, 18, 22, and 28.
What is the median wait time?
A) 20 minutes
B) 21 minutes
C) 22 minutes
D) 23 minutes
,E) 24 minutes
CORRECT ANSWER: B) 21 minutes
Rationale: To find the median, arrange the data in order: 15, 15, 18, 18, 20, 22, 22,
25, 28, 30. With 10 values (even number), the median is the average of the 5th and
6th values: (20 + 22) ÷ 2 = 21 minutes. The median is the middle value(s) in an
ordered dataset and is less affected by outliers than the mean.
QUESTION 2
A healthcare provider wants to understand the variation in patient
satisfaction scores across three different departments. Which measure would
best describe the spread of scores within each department?
A) The range only
B) The mode exclusively
C) Standard deviation and variance
D) The median alone
E) The interquartile range only
CORRECT ANSWER: C) Standard deviation and variance
Rationale: Standard deviation and variance are the most comprehensive measures
of spread, showing how individual scores deviate from the mean. While range and
interquartile range show spread, standard deviation and variance are more
sensitive to all data points and are more appropriate for comparing variation across
groups in statistical analysis and quality improvement initiatives.
QUESTION 3
In a normally distributed population of patient blood pressure readings, the
mean is 120 mmHg and the standard deviation is 10 mmHg. Approximately
what percentage of readings fall between 110 and 130 mmHg?
,A) 34%
B) 68%
C) 95%
D) 99.7%
E) 50%
CORRECT ANSWER: B) 68%
Rationale: According to the empirical rule (68-95-99.7 rule) for normal
distributions, approximately 68% of data falls within one standard deviation of the
mean. The range 110–130 mmHg represents mean ± 1 SD (120 ± 10), which
encompasses approximately 68% of the population in a normal distribution.
QUESTION 4
A hospital conducts a study to compare recovery times between two
treatment groups. Which statistical test would be most appropriate for
comparing the means of two independent groups?
A) Chi-square test
B) Independent samples t-test
C) Paired t-test
D) ANOVA
E) Correlation analysis
CORRECT ANSWER: B) Independent samples t-test
Rationale: An independent samples t-test is designed to compare the means of
two independent groups and determine if the difference is statistically significant.
Chi-square tests categorical data, paired t-tests compare dependent/matched
samples, ANOVA compares three or more groups, and correlation examines
relationships between variables, not group mean differences.
, QUESTION 5
A researcher collects data on patient age, collected as: <18, 18–30, 31–45, 46–
65, >65. What type of data measurement scale is this?
A) Nominal
B) Ordinal
C) Interval
D) Ratio
E) Continuous
CORRECT ANSWER: B) Ordinal
Rationale: Ordinal data has a natural order or ranking (age groups progress from
youngest to oldest) but the intervals between categories are not equal. Nominal
data has no order, interval data has equal intervals with no true zero, ratio data has
equal intervals with a true zero, and continuous data takes any value within a
range.
QUESTION 6
A healthcare facility wants to estimate the proportion of patients who
experience adverse events. A sample of 500 patients shows 45 adverse events.
What is the point estimate for the proportion?
A) 0.05
B) 0.09
C) 0.15
D) 0.20
E) 0.25
CORRECT ANSWER: B) 0.09
