WGU C207 OA Final Self-Assessment 350 Q&A (100% Verified
Answers) | Newest Update 2026
MULTIPLE CHOICES
1. A hospital wants to predict 30-day readmission risk using patient age, prior admissions, and lab values. Which
method is most appropriate?
A) Decision tree
B) Logistic regression
C) Linear regression
D) Time series
Answer: B
Logistic regression predicts a binary outcome (readmitted or not) from multiple predictors.
2. A manufacturing line produces metal rods with target length 100 mm. A sample has mean 100.5 mm, p = 0.03. At
α = 0.05, what conclusion?
A) Accept null; process is in control
B) Reject null; mean differs from 100 mm
C) Fail to reject null; no change needed
D) Accept alternative; variance is too high
Answer: B
Since p < 0.05, reject the null hypothesis that mean equals 100 mm.
3. Which metric indicates the proportion of true positives correctly identified by a binary classifier?
A) Precision
B) Recall (Sensitivity)
C) Specificity
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,D) Accuracy
Answer: B
Recall = TP/(TP+FN), measuring ability to find all actual positives.
4. A retailer notices sales spikes every December. This is an example of:
A) Cyclical variation
B) Seasonal variation
C) Trend variation
D) Random variation
Answer: B
Seasonal variation repeats at fixed intervals (e.g., yearly holidays).
5. A p-value of 0.002 in a regression coefficient means:
A) No relationship exists
B) Coefficient is significant at α = 0.01
C) Effect size is large
D) Multicollinearity is present
Answer: B
P-value below 0.01 indicates strong evidence against null, so coefficient is significant.
6. A manager sees that ice cream sales and drowning incidents are correlated. What can be concluded?
A) Ice cream causes drowning
B) A third factor (hot weather) influences both
C) Drowning causes ice cream sales
D) No relationship exists
Answer: B
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,Correlation does not equal causation; a confounding variable is likely.
7. In a control chart, a point above the upper control limit likely indicates:
A) Common cause variation
B) Special cause variation
C) Measurement error
D) Expected process behavior
Answer: B
Points outside control limits signal special cause variation requiring investigation.
8. A data set has mean 50, median 60. The distribution is:
A) Symmetric
B) Left-skewed
C) Right-skewed
D) Uniform
Answer: C
Mean < median indicates negative skew? Wait correction: Mean 50, median 60 → mean left of median = left-
skewed (negative). Actually: mean < median → left skew. But common confusion: right skew has mean > median.
Here mean 50 < median 60 = left-skewed. Answer B. (Double-check: left tail longer → mean pulled left.)
9. A logistic regression coefficient of 0.8 for “marketing email” (p=0.01) means:
A) Email increases odds of purchase by factor e^0.8
B) Email decreases probability by 80%
C) Email has no effect
D) Model is overfit
Answer: A
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, Positive coefficient increases odds; exponentiate to get odds ratio.
10. Which Big Data V refers to inconsistency in data formats?
A) Volume
B) Velocity
C) Variety
D) Veracity
Answer: D
Veracity captures data quality, accuracy, and trustworthiness issues.
11. A test has 95% sensitivity and 90% specificity in a population with 10% disease prevalence. What is the
probability a positive result truly has disease?
A) 95%
B) 51%
C) 10%
D) 90%
Answer: B
Positive predictive value = (sensprev)/(sens prev + (1-spec)(1-prev)) ≈ (0.95*0.1)/(0.095+0.09)=0.095/0.185≈0.514.
12. A p-value is defined as:
A) Probability null is true
B) Probability of observed data if null is true
C) Probability alternative is true
D) Effect size
Answer: B
P-value measures evidence against null, assuming null is true.
4|Page SUCCESS!!!
Answers) | Newest Update 2026
MULTIPLE CHOICES
1. A hospital wants to predict 30-day readmission risk using patient age, prior admissions, and lab values. Which
method is most appropriate?
A) Decision tree
B) Logistic regression
C) Linear regression
D) Time series
Answer: B
Logistic regression predicts a binary outcome (readmitted or not) from multiple predictors.
2. A manufacturing line produces metal rods with target length 100 mm. A sample has mean 100.5 mm, p = 0.03. At
α = 0.05, what conclusion?
A) Accept null; process is in control
B) Reject null; mean differs from 100 mm
C) Fail to reject null; no change needed
D) Accept alternative; variance is too high
Answer: B
Since p < 0.05, reject the null hypothesis that mean equals 100 mm.
3. Which metric indicates the proportion of true positives correctly identified by a binary classifier?
A) Precision
B) Recall (Sensitivity)
C) Specificity
1|Page SUCCESS!!!
,D) Accuracy
Answer: B
Recall = TP/(TP+FN), measuring ability to find all actual positives.
4. A retailer notices sales spikes every December. This is an example of:
A) Cyclical variation
B) Seasonal variation
C) Trend variation
D) Random variation
Answer: B
Seasonal variation repeats at fixed intervals (e.g., yearly holidays).
5. A p-value of 0.002 in a regression coefficient means:
A) No relationship exists
B) Coefficient is significant at α = 0.01
C) Effect size is large
D) Multicollinearity is present
Answer: B
P-value below 0.01 indicates strong evidence against null, so coefficient is significant.
6. A manager sees that ice cream sales and drowning incidents are correlated. What can be concluded?
A) Ice cream causes drowning
B) A third factor (hot weather) influences both
C) Drowning causes ice cream sales
D) No relationship exists
Answer: B
2|Page SUCCESS!!!
,Correlation does not equal causation; a confounding variable is likely.
7. In a control chart, a point above the upper control limit likely indicates:
A) Common cause variation
B) Special cause variation
C) Measurement error
D) Expected process behavior
Answer: B
Points outside control limits signal special cause variation requiring investigation.
8. A data set has mean 50, median 60. The distribution is:
A) Symmetric
B) Left-skewed
C) Right-skewed
D) Uniform
Answer: C
Mean < median indicates negative skew? Wait correction: Mean 50, median 60 → mean left of median = left-
skewed (negative). Actually: mean < median → left skew. But common confusion: right skew has mean > median.
Here mean 50 < median 60 = left-skewed. Answer B. (Double-check: left tail longer → mean pulled left.)
9. A logistic regression coefficient of 0.8 for “marketing email” (p=0.01) means:
A) Email increases odds of purchase by factor e^0.8
B) Email decreases probability by 80%
C) Email has no effect
D) Model is overfit
Answer: A
3|Page SUCCESS!!!
, Positive coefficient increases odds; exponentiate to get odds ratio.
10. Which Big Data V refers to inconsistency in data formats?
A) Volume
B) Velocity
C) Variety
D) Veracity
Answer: D
Veracity captures data quality, accuracy, and trustworthiness issues.
11. A test has 95% sensitivity and 90% specificity in a population with 10% disease prevalence. What is the
probability a positive result truly has disease?
A) 95%
B) 51%
C) 10%
D) 90%
Answer: B
Positive predictive value = (sensprev)/(sens prev + (1-spec)(1-prev)) ≈ (0.95*0.1)/(0.095+0.09)=0.095/0.185≈0.514.
12. A p-value is defined as:
A) Probability null is true
B) Probability of observed data if null is true
C) Probability alternative is true
D) Effect size
Answer: B
P-value measures evidence against null, assuming null is true.
4|Page SUCCESS!!!
