C784 Applied Healthcare Statistics OA Practice Exam 2026 |WGU
1. Which level of measurement is used for data that can be categorized into
groups but has no inherent order?
A. Interval
B. Nominal
C. Ordinal
D. Ratio
Answer: B
Rationale: Nominal data represents categories that do not have a natural rank or order,
such as gender or eye color.
2. In a right-skewed distribution, which measure of central tendency is typically
the largest?
A. Median
B. Mean
C. Mode
D. Range
Answer: B
Rationale: In a right-skewed distribution, the tail is on the right, pulling the mean toward
the higher values, making it greater than the median and mode.
,3. Which of the following describes a Type I error?
A. Rejecting a true null hypothesis
B. Failing to reject a false null hypothesis
C. Rejecting a false null hypothesis
D. Failing to reject a true null hypothesis
Answer: A
Rationale: A Type I error occurs when the null hypothesis is actually true, but the
researcher mistakenly rejects it (a false positive).
4. What is the standard deviation of a dataset if the variance is 25?
A. 12.5
B. 50
C. 625
D. 5
Answer: D
Rationale: The standard deviation is the square root of the variance. The square root of 25
is 5.
5. A researcher selects every 10th person from a list of hospital patients. What
sampling method is being used?
A. Systematic sampling
B. Cluster sampling
C. Stratified sampling
D. Simple random sampling
Answer: A
Rationale: Systematic sampling involves selecting members from a population according
to a random starting point and a fixed, periodic interval.
, 6. What percentage of data falls within two standard deviations of the mean in
a normal distribution?
A. 68%
B. 99.7%
C. 50%
D. 95%
Answer: D
Rationale: According to the Empirical Rule (68-95-99.7), approximately 95% of data falls
within two standard deviations of the mean.
7. Which correlation coefficient represents the strongest relationship between
two variables?
A. 0.75
B. 0.10
C. -0.85
D. -0.50
Answer: C
Rationale: The strength of a correlation is determined by the absolute value of the
coefficient. 0.85 is higher than 0.75, regardless of the negative sign.
8. What does a p-value of 0.03 indicate if the significance level (alpha) is 0.05?
A. Fail to reject the null hypothesis
B. The results are not statistically significant
C. The alternative hypothesis is false
D. Reject the null hypothesis
Answer: D
Rationale: If the p-value is less than or equal to alpha, the results are statistically
significant, and the null hypothesis is rejected.
1. Which level of measurement is used for data that can be categorized into
groups but has no inherent order?
A. Interval
B. Nominal
C. Ordinal
D. Ratio
Answer: B
Rationale: Nominal data represents categories that do not have a natural rank or order,
such as gender or eye color.
2. In a right-skewed distribution, which measure of central tendency is typically
the largest?
A. Median
B. Mean
C. Mode
D. Range
Answer: B
Rationale: In a right-skewed distribution, the tail is on the right, pulling the mean toward
the higher values, making it greater than the median and mode.
,3. Which of the following describes a Type I error?
A. Rejecting a true null hypothesis
B. Failing to reject a false null hypothesis
C. Rejecting a false null hypothesis
D. Failing to reject a true null hypothesis
Answer: A
Rationale: A Type I error occurs when the null hypothesis is actually true, but the
researcher mistakenly rejects it (a false positive).
4. What is the standard deviation of a dataset if the variance is 25?
A. 12.5
B. 50
C. 625
D. 5
Answer: D
Rationale: The standard deviation is the square root of the variance. The square root of 25
is 5.
5. A researcher selects every 10th person from a list of hospital patients. What
sampling method is being used?
A. Systematic sampling
B. Cluster sampling
C. Stratified sampling
D. Simple random sampling
Answer: A
Rationale: Systematic sampling involves selecting members from a population according
to a random starting point and a fixed, periodic interval.
, 6. What percentage of data falls within two standard deviations of the mean in
a normal distribution?
A. 68%
B. 99.7%
C. 50%
D. 95%
Answer: D
Rationale: According to the Empirical Rule (68-95-99.7), approximately 95% of data falls
within two standard deviations of the mean.
7. Which correlation coefficient represents the strongest relationship between
two variables?
A. 0.75
B. 0.10
C. -0.85
D. -0.50
Answer: C
Rationale: The strength of a correlation is determined by the absolute value of the
coefficient. 0.85 is higher than 0.75, regardless of the negative sign.
8. What does a p-value of 0.03 indicate if the significance level (alpha) is 0.05?
A. Fail to reject the null hypothesis
B. The results are not statistically significant
C. The alternative hypothesis is false
D. Reject the null hypothesis
Answer: D
Rationale: If the p-value is less than or equal to alpha, the results are statistically
significant, and the null hypothesis is rejected.
