Fall 2025 – Spring 2026 | WGU C784 Applied Healthcare
Statistics Complete Study Guide With 300 Exam-Style
Questions | Updated 2025–2026 WGU C784 Objective
Assessment Prep, Statistical Analysis, Healthcare
Data Interpretation, Probability, Sampling Methods,
Research Application & High-Yield OA Success Notes
1. Which of the following measures is used to describe the central tendency of a
data set?
• A) Mode
• B) Variance
• C) Standard Deviation
• D) Range
CORRECT ANSWER: A) Mode
Rationale: The mode is the value that appears most frequently in a data set and is a
measure of central tendency. Variance and standard deviation measure dispersion, and
the range represents the difference between the maximum and minimum values.
2. In a normal distribution, what percentage of data falls within one standard
deviation of the mean?
• A) 50%
• B) 68%
• C) 95%
• D) 99.7%
CORRECT ANSWER: B) 68%
Rationale: In a normal distribution, approximately 68% of the data falls within one
standard deviation of the mean, according to the empirical rule.
3. What is the primary purpose of using a p-value in hypothesis testing?
• A) To determine the strength of a relationship
• B) To measure the central tendency
• C) To provide evidence against the null hypothesis
• D) To calculate variance
CORRECT ANSWER: C) To provide evidence against the null hypothesis
,Rationale: A p-value helps determine the significance of results in hypothesis testing,
specifically showing how unlikely the observed data would be if the null hypothesis
were true.
4. Which of the following types of studies is best suited for establishing causal
relationships?
• A) Descriptive study
• B) Randomized controlled trial
• C) Observational study
• D) Cross-sectional study
CORRECT ANSWER: B) Randomized controlled trial
Rationale: Randomized controlled trials (RCTs) are considered the gold standard for
establishing causal relationships due to their design, which minimizes bias and allows
for the manipulation of variables.
5. What term describes the probability of rejecting the null hypothesis when it is
actually true?
• A) Type I error
• B) Type II error
• C) Confidence interval
• D) Power
CORRECT ANSWER: A) Type I error
Rationale: A Type I error occurs when a true null hypothesis is incorrectly rejected,
often associated with a significance level (alpha) in hypothesis testing.
6. In statistical terms, what does "n" typically represent?
• A) The mean
• B) The population size
• C) The sample size
• D) The standard deviation
CORRECT ANSWER: C) The sample size
Rationale: In statistics, "n" commonly denotes the size of the sample being analyzed.
,7. Which statistical test is appropriate for comparing the means of two
independent groups?
• A) Paired t-test
• B) ANOVA
• C) Independent t-test
• D) Chi-square test
CORRECT ANSWER: C) Independent t-test
Rationale: The independent t-test is specifically designed to compare the means of two
independent groups.
8. What does a confidence interval provide in statistical analysis?
• A) A precise value of the population mean
• B) A range of values within which the population parameter lies with a certain
probability
• C) A measure of data dispersion
• D) A comparison of two population means
CORRECT ANSWER: B) A range of values within which the population parameter lies
with a certain probability
Rationale: A confidence interval estimates the range of values likely to contain the
population parameter, providing a degree of uncertainty.
9. In healthcare statistics, what is the purpose of regression analysis?
• A) To summarize data
• B) To determine the frequency of events
• C) To establish relationships between variables
• D) To calculate averages
CORRECT ANSWER: C) To establish relationships between variables
Rationale: Regression analysis is used to identify and quantify relationships between
dependent and independent variables.
10. What is a common use of descriptive statistics?
, • A) Testing hypotheses
• B) Making predictions
• C) Summarizing and describing data
• D) Evaluating causality
CORRECT ANSWER: C) Summarizing and describing data
Rationale: Descriptive statistics help summarize and describe the main features of a
dataset.
11. When analyzing categorical data, which statistical test would be most
appropriate?
• A) ANOVA
• B) Chi-square test
• C) Pearson correlation
• D) t-test
CORRECT ANSWER: B) Chi-square test
Rationale: The Chi-square test is specifically designed for analyzing relationships
between categorical variables.
12. What does it mean if a study has a power of 0.80?
• A) There is an 80% chance of detecting a true effect
• B) There is a 20% chance of making a Type I error
• C) It is statistically insignificant
• D) It cannot detect any effects
CORRECT ANSWER: A) There is an 80% chance of detecting a true effect
Rationale: A power of 0.80 indicates that there is an 80% probability of correctly
rejecting the null hypothesis when it is false.
13. Which of the following is a non-parametric test?
• A) ANOVA
• B) t-test
• C) Mann-Whitney U test
Statistics Complete Study Guide With 300 Exam-Style
Questions | Updated 2025–2026 WGU C784 Objective
Assessment Prep, Statistical Analysis, Healthcare
Data Interpretation, Probability, Sampling Methods,
Research Application & High-Yield OA Success Notes
1. Which of the following measures is used to describe the central tendency of a
data set?
• A) Mode
• B) Variance
• C) Standard Deviation
• D) Range
CORRECT ANSWER: A) Mode
Rationale: The mode is the value that appears most frequently in a data set and is a
measure of central tendency. Variance and standard deviation measure dispersion, and
the range represents the difference between the maximum and minimum values.
2. In a normal distribution, what percentage of data falls within one standard
deviation of the mean?
• A) 50%
• B) 68%
• C) 95%
• D) 99.7%
CORRECT ANSWER: B) 68%
Rationale: In a normal distribution, approximately 68% of the data falls within one
standard deviation of the mean, according to the empirical rule.
3. What is the primary purpose of using a p-value in hypothesis testing?
• A) To determine the strength of a relationship
• B) To measure the central tendency
• C) To provide evidence against the null hypothesis
• D) To calculate variance
CORRECT ANSWER: C) To provide evidence against the null hypothesis
,Rationale: A p-value helps determine the significance of results in hypothesis testing,
specifically showing how unlikely the observed data would be if the null hypothesis
were true.
4. Which of the following types of studies is best suited for establishing causal
relationships?
• A) Descriptive study
• B) Randomized controlled trial
• C) Observational study
• D) Cross-sectional study
CORRECT ANSWER: B) Randomized controlled trial
Rationale: Randomized controlled trials (RCTs) are considered the gold standard for
establishing causal relationships due to their design, which minimizes bias and allows
for the manipulation of variables.
5. What term describes the probability of rejecting the null hypothesis when it is
actually true?
• A) Type I error
• B) Type II error
• C) Confidence interval
• D) Power
CORRECT ANSWER: A) Type I error
Rationale: A Type I error occurs when a true null hypothesis is incorrectly rejected,
often associated with a significance level (alpha) in hypothesis testing.
6. In statistical terms, what does "n" typically represent?
• A) The mean
• B) The population size
• C) The sample size
• D) The standard deviation
CORRECT ANSWER: C) The sample size
Rationale: In statistics, "n" commonly denotes the size of the sample being analyzed.
,7. Which statistical test is appropriate for comparing the means of two
independent groups?
• A) Paired t-test
• B) ANOVA
• C) Independent t-test
• D) Chi-square test
CORRECT ANSWER: C) Independent t-test
Rationale: The independent t-test is specifically designed to compare the means of two
independent groups.
8. What does a confidence interval provide in statistical analysis?
• A) A precise value of the population mean
• B) A range of values within which the population parameter lies with a certain
probability
• C) A measure of data dispersion
• D) A comparison of two population means
CORRECT ANSWER: B) A range of values within which the population parameter lies
with a certain probability
Rationale: A confidence interval estimates the range of values likely to contain the
population parameter, providing a degree of uncertainty.
9. In healthcare statistics, what is the purpose of regression analysis?
• A) To summarize data
• B) To determine the frequency of events
• C) To establish relationships between variables
• D) To calculate averages
CORRECT ANSWER: C) To establish relationships between variables
Rationale: Regression analysis is used to identify and quantify relationships between
dependent and independent variables.
10. What is a common use of descriptive statistics?
, • A) Testing hypotheses
• B) Making predictions
• C) Summarizing and describing data
• D) Evaluating causality
CORRECT ANSWER: C) Summarizing and describing data
Rationale: Descriptive statistics help summarize and describe the main features of a
dataset.
11. When analyzing categorical data, which statistical test would be most
appropriate?
• A) ANOVA
• B) Chi-square test
• C) Pearson correlation
• D) t-test
CORRECT ANSWER: B) Chi-square test
Rationale: The Chi-square test is specifically designed for analyzing relationships
between categorical variables.
12. What does it mean if a study has a power of 0.80?
• A) There is an 80% chance of detecting a true effect
• B) There is a 20% chance of making a Type I error
• C) It is statistically insignificant
• D) It cannot detect any effects
CORRECT ANSWER: A) There is an 80% chance of detecting a true effect
Rationale: A power of 0.80 indicates that there is an 80% probability of correctly
rejecting the null hypothesis when it is false.
13. Which of the following is a non-parametric test?
• A) ANOVA
• B) t-test
• C) Mann-Whitney U test
