WGU C784 Applied Healthcare Statistics
Final Assessment Exam (2025/2026) –
Complete 70 Questions Fully Solved |
100% Original | Graded A+
LATEST 2025 VERSION | 70 QUESTIONS FULLY SOLVED | GRADED A+ | 100%
ORIGINAL VERIFIED ANSWERS IN RED | DETAILED RATIONALES WITH
FORMULAS
Q1. What is the purpose of descriptive statistics? To summarize and describe data
characteristics. Rationale: Descriptive stats (mean, median, mode) organize raw data for
interpretation; inferential stats make predictions.
Q2. The mean of the data set {2, 4, 4, 4, 5, 5, 7, 9} is: 5. Rationale: Sum = 40, n = 8, mean =
40/8 = 5.
Q3. Which measure of central tendency is least affected by outliers? Median. Rationale:
Median is the middle value; mean pulled by extremes, mode by frequency.
Q4. The standard deviation measures: Dispersion of data around the mean. Rationale:
√variance; higher SD = more spread.
Q5. In a normal distribution, what percentage of data falls within 1 SD of the mean? 68%.
Rationale: Empirical rule: 68% within 1 SD, 95% within 2, 99.7% within 3.
Q6. What is the range of the data set {12, 15, 18, 22, 25}? 13. Rationale: Max – min = 25 – 12 =
13.
, Q7. Mode of {1, 2, 2, 3, 4, 4, 4, 5}? 4. Rationale: Appears most frequently (3 times).
Q8. Variance formula for population? Σ(X – μ)² / N. Rationale: Sample uses n-1 for unbiased
estimate.
Q9. Skewness describes: Asymmetry of distribution. Rationale: Positive skew = tail right;
negative = left.
Q10. What is a z-score? Standard deviations from mean. Rationale: Z = (X – μ) / σ.
Q11. Probability of rolling a 6 on a die? 1/6. Rationale: 1 favorable / 6 possible outcomes.
Q12. P(A or B) = P(A) + P(B) – ? P(A and B). Rationale: Addition rule for union.
Q13. What is a Type I error? Rejecting true null hypothesis. Rationale: False positive; alpha =
significance level.
Q14. P-value < 0.05 means: Reject null hypothesis at 5% level. Rationale: Statistically
significant.
Q15. Confidence interval 95% means: 95% of intervals contain true parameter. Rationale:
Not probability for single interval.
Q16. t-test used when: Small sample, unknown population SD. Rationale: Z-test for large
samples/known SD.
Final Assessment Exam (2025/2026) –
Complete 70 Questions Fully Solved |
100% Original | Graded A+
LATEST 2025 VERSION | 70 QUESTIONS FULLY SOLVED | GRADED A+ | 100%
ORIGINAL VERIFIED ANSWERS IN RED | DETAILED RATIONALES WITH
FORMULAS
Q1. What is the purpose of descriptive statistics? To summarize and describe data
characteristics. Rationale: Descriptive stats (mean, median, mode) organize raw data for
interpretation; inferential stats make predictions.
Q2. The mean of the data set {2, 4, 4, 4, 5, 5, 7, 9} is: 5. Rationale: Sum = 40, n = 8, mean =
40/8 = 5.
Q3. Which measure of central tendency is least affected by outliers? Median. Rationale:
Median is the middle value; mean pulled by extremes, mode by frequency.
Q4. The standard deviation measures: Dispersion of data around the mean. Rationale:
√variance; higher SD = more spread.
Q5. In a normal distribution, what percentage of data falls within 1 SD of the mean? 68%.
Rationale: Empirical rule: 68% within 1 SD, 95% within 2, 99.7% within 3.
Q6. What is the range of the data set {12, 15, 18, 22, 25}? 13. Rationale: Max – min = 25 – 12 =
13.
, Q7. Mode of {1, 2, 2, 3, 4, 4, 4, 5}? 4. Rationale: Appears most frequently (3 times).
Q8. Variance formula for population? Σ(X – μ)² / N. Rationale: Sample uses n-1 for unbiased
estimate.
Q9. Skewness describes: Asymmetry of distribution. Rationale: Positive skew = tail right;
negative = left.
Q10. What is a z-score? Standard deviations from mean. Rationale: Z = (X – μ) / σ.
Q11. Probability of rolling a 6 on a die? 1/6. Rationale: 1 favorable / 6 possible outcomes.
Q12. P(A or B) = P(A) + P(B) – ? P(A and B). Rationale: Addition rule for union.
Q13. What is a Type I error? Rejecting true null hypothesis. Rationale: False positive; alpha =
significance level.
Q14. P-value < 0.05 means: Reject null hypothesis at 5% level. Rationale: Statistically
significant.
Q15. Confidence interval 95% means: 95% of intervals contain true parameter. Rationale:
Not probability for single interval.
Q16. t-test used when: Small sample, unknown population SD. Rationale: Z-test for large
samples/known SD.
