WGU C784 - APPLIED HEALTHCARE
STATISTICS OBJECTIVE
ASSESSMENT EXAM QUESTIONS
AND 100% VERIFIED ANSWERS
WITH RATIONALES GRADED A+
LATEST
1. A hospital wants to compare the mean length of stay for patients in two different
units. Unit A has 30 patients with a mean stay of 5.2 days (SD = 1.1), and Unit B
has 25 patients with a mean stay of 4.7 days (SD = 1.3). Which statistical test is
most appropriate to determine if the difference is significant?
A. Chi-square test
B. Paired t-test
C. Independent t-test
D. ANOVA
Answer: C. Independent t-test
Rationale: The two units are independent groups, and we are comparing the means
of a continuous variable, which calls for an independent t-test.
2. In a normal distribution, approximately what percentage of values fall within
one standard deviation of the mean?
A. 50%
B. 68%
C. 95%
D. 99%
Answer: B. 68%
Rationale: By the empirical rule, roughly 68% of data in a normal distribution lie
within ±1 SD of the mean.
,3. A researcher finds a correlation coefficient of r = 0.82 between patient
satisfaction scores and nurse staffing levels. How should this be interpreted?
A. Weak positive correlation
B. Strong positive correlation
C. Weak negative correlation
D. Strong negative correlation
Answer: B. Strong positive correlation
Rationale: Correlation values range from -1 to +1; 0.82 indicates a strong positive
relationship.
4. A study reports that the p-value for a treatment effect is 0.03. If α = 0.05, what is
the correct conclusion?
A. Fail to reject the null hypothesis
B. Reject the null hypothesis
C. Accept the null hypothesis
D. Increase the sample size
Answer: B. Reject the null hypothesis
Rationale: p < α indicates sufficient evidence to reject the null hypothesis.
5. Which measure of central tendency is most appropriate when the data are highly
skewed?
A. Mean
B. Median
C. Mode
D. Range
Answer: B. Median
Rationale: The median is resistant to extreme values, making it better for skewed
distributions.
,6. A hospital tracks readmission rates across 5 departments. Which statistical test is
appropriate for comparing proportions across multiple independent groups?
A. ANOVA
B. Chi-square test of independence
C. Paired t-test
D. Linear regression
Answer: B. Chi-square test of independence
Rationale: Proportions across independent categorical groups are analyzed with a
chi-square test.
7. If a confidence interval for the mean length of stay is 4.5–5.3 days (95% CI),
which of the following is correct?
A. 95% of individual patient stays fall between 4.5–5.3 days
B. We are 95% confident that the true mean stay falls between 4.5–5.3 days
C. The mean stay is exactly 4.9 days
D. 95% of future sample means will fall in this interval
Answer: B. We are 95% confident that the true mean stay falls between 4.5–5.3
days
Rationale: Confidence intervals estimate the range in which the population
parameter likely falls.
8. Which type of variable is “blood type” (A, B, AB, O)?
A. Nominal
B. Ordinal
C. Interval
D. Ratio
Answer: A. Nominal
Rationale: Blood type categories are named categories with no intrinsic order.
, 9. A researcher calculates a standard deviation of 2.5 for patient wait times. What
does this indicate?
A. Average wait time
B. Variability of wait times around the mean
C. Maximum wait time
D. Correlation between wait time and satisfaction
Answer: B. Variability of wait times around the mean
Rationale: Standard deviation quantifies spread around the mean.
10. In a regression analysis predicting patient satisfaction, the coefficient for nurse
hours per patient is 0.45. What does this mean?
A. Satisfaction decreases as nurse hours increase
B. Satisfaction increases by 0.45 units per additional nurse hour
C. Satisfaction is unrelated to nurse hours
D. Nurse hours explain 45% of satisfaction
Answer: B. Satisfaction increases by 0.45 units per additional nurse hour
Rationale: Regression coefficients indicate the expected change in the dependent
variable per unit change in the predictor.
11. Which type of sampling minimizes selection bias in a healthcare study?
A. Convenience sampling
B. Random sampling
C. Snowball sampling
D. Purposive sampling
Answer: B. Random sampling
Rationale: Random sampling ensures each member of the population has an equal
chance of selection.
STATISTICS OBJECTIVE
ASSESSMENT EXAM QUESTIONS
AND 100% VERIFIED ANSWERS
WITH RATIONALES GRADED A+
LATEST
1. A hospital wants to compare the mean length of stay for patients in two different
units. Unit A has 30 patients with a mean stay of 5.2 days (SD = 1.1), and Unit B
has 25 patients with a mean stay of 4.7 days (SD = 1.3). Which statistical test is
most appropriate to determine if the difference is significant?
A. Chi-square test
B. Paired t-test
C. Independent t-test
D. ANOVA
Answer: C. Independent t-test
Rationale: The two units are independent groups, and we are comparing the means
of a continuous variable, which calls for an independent t-test.
2. In a normal distribution, approximately what percentage of values fall within
one standard deviation of the mean?
A. 50%
B. 68%
C. 95%
D. 99%
Answer: B. 68%
Rationale: By the empirical rule, roughly 68% of data in a normal distribution lie
within ±1 SD of the mean.
,3. A researcher finds a correlation coefficient of r = 0.82 between patient
satisfaction scores and nurse staffing levels. How should this be interpreted?
A. Weak positive correlation
B. Strong positive correlation
C. Weak negative correlation
D. Strong negative correlation
Answer: B. Strong positive correlation
Rationale: Correlation values range from -1 to +1; 0.82 indicates a strong positive
relationship.
4. A study reports that the p-value for a treatment effect is 0.03. If α = 0.05, what is
the correct conclusion?
A. Fail to reject the null hypothesis
B. Reject the null hypothesis
C. Accept the null hypothesis
D. Increase the sample size
Answer: B. Reject the null hypothesis
Rationale: p < α indicates sufficient evidence to reject the null hypothesis.
5. Which measure of central tendency is most appropriate when the data are highly
skewed?
A. Mean
B. Median
C. Mode
D. Range
Answer: B. Median
Rationale: The median is resistant to extreme values, making it better for skewed
distributions.
,6. A hospital tracks readmission rates across 5 departments. Which statistical test is
appropriate for comparing proportions across multiple independent groups?
A. ANOVA
B. Chi-square test of independence
C. Paired t-test
D. Linear regression
Answer: B. Chi-square test of independence
Rationale: Proportions across independent categorical groups are analyzed with a
chi-square test.
7. If a confidence interval for the mean length of stay is 4.5–5.3 days (95% CI),
which of the following is correct?
A. 95% of individual patient stays fall between 4.5–5.3 days
B. We are 95% confident that the true mean stay falls between 4.5–5.3 days
C. The mean stay is exactly 4.9 days
D. 95% of future sample means will fall in this interval
Answer: B. We are 95% confident that the true mean stay falls between 4.5–5.3
days
Rationale: Confidence intervals estimate the range in which the population
parameter likely falls.
8. Which type of variable is “blood type” (A, B, AB, O)?
A. Nominal
B. Ordinal
C. Interval
D. Ratio
Answer: A. Nominal
Rationale: Blood type categories are named categories with no intrinsic order.
, 9. A researcher calculates a standard deviation of 2.5 for patient wait times. What
does this indicate?
A. Average wait time
B. Variability of wait times around the mean
C. Maximum wait time
D. Correlation between wait time and satisfaction
Answer: B. Variability of wait times around the mean
Rationale: Standard deviation quantifies spread around the mean.
10. In a regression analysis predicting patient satisfaction, the coefficient for nurse
hours per patient is 0.45. What does this mean?
A. Satisfaction decreases as nurse hours increase
B. Satisfaction increases by 0.45 units per additional nurse hour
C. Satisfaction is unrelated to nurse hours
D. Nurse hours explain 45% of satisfaction
Answer: B. Satisfaction increases by 0.45 units per additional nurse hour
Rationale: Regression coefficients indicate the expected change in the dependent
variable per unit change in the predictor.
11. Which type of sampling minimizes selection bias in a healthcare study?
A. Convenience sampling
B. Random sampling
C. Snowball sampling
D. Purposive sampling
Answer: B. Random sampling
Rationale: Random sampling ensures each member of the population has an equal
chance of selection.
