WGU C207 Driven Decision Making
Questions and Answers
(2022/2025) (Verified Answers)
GRADED
Section 1: Descriptive Statistics
1. The exam scores are: 60, 70, 70, 80, 90. What is the median?
• Answer: 70
• Rationale: Ordered values = [60, 70, 70, 80, 90]. Middle value
= 70.
2. A dataset has mean = 100, SD = 20. A score of 140 is how many
standard deviations above the mean?
• Answer: 2
• Rationale: (140–100)/20 = 40/20 = 2.
,3. Which is the most appropriate measure of central tendency for
skewed data?
• Answer: Median
• Rationale: Median is less influenced by skew/outliers.
4. The variance of dataset {4, 6, 8} is?
• Answer: 4
• Rationale: Mean = 6. Deviations: (–2, 0, +2). Squared = (4, 0,
4). Average = 8/2 (population) = 4.
5. A boxplot shows a very long whisker on the right. This suggests:
• Answer: Right skew (positive skew)
• Rationale: Longer tail in the positive direction.
6. What does a coefficient of variation (CV) measure?
• Answer: Relative variability compared to the mean
• Rationale: CV = (SD/mean) × 100%.
7. Which dataset has the greatest spread?
• A: {5, 6, 7, 8}
• B: {5, 10, 15, 20}
• Answer: B
• Rationale: Wider range and higher SD.
8. A frequency table is best used for:
• Answer: Summarizing categorical or discrete data
• Rationale: Shows counts per category.
9. If the mean = median = mode, the distribution is:
• Answer: Symmetric and normal
, • Rationale: Equal measures indicate no skew.
10. Outliers most affect which statistic?
• Answer: Mean
• Rationale: Extreme values pull the mean more than the
median.
Section 2: Probability & Decision Models
11. Toss 2 coins. Probability of exactly one head?
• Answer: 0.5
• Rationale: Possible outcomes: HH, HT, TH, TT. Favorable = 2/4
= 0.5.
12. If P(A)=0.4 and P(B)=0.3 and they are mutually exclusive,
P(A∪B)=?
• Answer: 0.7
• Rationale: Mutually exclusive → add probabilities.
13. A machine produces 95% good parts. If 2 are chosen, probability
both are good?
• Answer: 0.9025
• Rationale: 0.95 × 0.95 = 0.9025.
14. Which distribution is appropriate for number of successes in
fixed trials?
• Answer: Binomial
, • Rationale: Binary outcomes, fixed trials, constant probability.
15. Expected monetary value (EMV) is calculated by:
• Answer: Multiplying each outcome by its probability and
summing
• Rationale: Weighted average of payoffs.
16. A risk-averse manager might prefer:
• Answer: Option with lower variability even if EV is smaller
• Rationale: They trade some profit for reduced risk.
17. In a normal distribution, about 95% of data fall within:
• Answer: ±2 standard deviations of mean
• Rationale: Empirical rule.
18. Bayes’ theorem is useful when:
• Answer: Updating probabilities with new evidence
• Rationale: Revises prior probability into posterior.
19. Decision tree branches represent:
• Answer: Possible decisions and outcomes
• Rationale: Graphical model of choices under uncertainty.
20. The probability of an impossible event is:
• Answer: 0
• Rationale: Cannot occur.
Section 3: Inferential Statistics
21. A researcher tests H₀: μ=50 vs H₁: μ≠50. This is a:
Questions and Answers
(2022/2025) (Verified Answers)
GRADED
Section 1: Descriptive Statistics
1. The exam scores are: 60, 70, 70, 80, 90. What is the median?
• Answer: 70
• Rationale: Ordered values = [60, 70, 70, 80, 90]. Middle value
= 70.
2. A dataset has mean = 100, SD = 20. A score of 140 is how many
standard deviations above the mean?
• Answer: 2
• Rationale: (140–100)/20 = 40/20 = 2.
,3. Which is the most appropriate measure of central tendency for
skewed data?
• Answer: Median
• Rationale: Median is less influenced by skew/outliers.
4. The variance of dataset {4, 6, 8} is?
• Answer: 4
• Rationale: Mean = 6. Deviations: (–2, 0, +2). Squared = (4, 0,
4). Average = 8/2 (population) = 4.
5. A boxplot shows a very long whisker on the right. This suggests:
• Answer: Right skew (positive skew)
• Rationale: Longer tail in the positive direction.
6. What does a coefficient of variation (CV) measure?
• Answer: Relative variability compared to the mean
• Rationale: CV = (SD/mean) × 100%.
7. Which dataset has the greatest spread?
• A: {5, 6, 7, 8}
• B: {5, 10, 15, 20}
• Answer: B
• Rationale: Wider range and higher SD.
8. A frequency table is best used for:
• Answer: Summarizing categorical or discrete data
• Rationale: Shows counts per category.
9. If the mean = median = mode, the distribution is:
• Answer: Symmetric and normal
, • Rationale: Equal measures indicate no skew.
10. Outliers most affect which statistic?
• Answer: Mean
• Rationale: Extreme values pull the mean more than the
median.
Section 2: Probability & Decision Models
11. Toss 2 coins. Probability of exactly one head?
• Answer: 0.5
• Rationale: Possible outcomes: HH, HT, TH, TT. Favorable = 2/4
= 0.5.
12. If P(A)=0.4 and P(B)=0.3 and they are mutually exclusive,
P(A∪B)=?
• Answer: 0.7
• Rationale: Mutually exclusive → add probabilities.
13. A machine produces 95% good parts. If 2 are chosen, probability
both are good?
• Answer: 0.9025
• Rationale: 0.95 × 0.95 = 0.9025.
14. Which distribution is appropriate for number of successes in
fixed trials?
• Answer: Binomial
, • Rationale: Binary outcomes, fixed trials, constant probability.
15. Expected monetary value (EMV) is calculated by:
• Answer: Multiplying each outcome by its probability and
summing
• Rationale: Weighted average of payoffs.
16. A risk-averse manager might prefer:
• Answer: Option with lower variability even if EV is smaller
• Rationale: They trade some profit for reduced risk.
17. In a normal distribution, about 95% of data fall within:
• Answer: ±2 standard deviations of mean
• Rationale: Empirical rule.
18. Bayes’ theorem is useful when:
• Answer: Updating probabilities with new evidence
• Rationale: Revises prior probability into posterior.
19. Decision tree branches represent:
• Answer: Possible decisions and outcomes
• Rationale: Graphical model of choices under uncertainty.
20. The probability of an impossible event is:
• Answer: 0
• Rationale: Cannot occur.
Section 3: Inferential Statistics
21. A researcher tests H₀: μ=50 vs H₁: μ≠50. This is a:
