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WGU D486 DFN1 Task 1 EXAM WITH COMPLETE 250 REAL
EXAM QUESTIONS AND CORRECT DETAILED ANSWERS
(VERIFIED ANSWERS) ALREADY GRADED A+
**1.** A data analyst is asked to evaluate a dataset before it is used to
support an organizational decision. The dataset contains missing values,
inconsistent formats, duplicate records, and several extreme
observations. What should the analyst do FIRST?
A. Build the final predictive model immediately.
B. Perform data-quality assessment and determine how the identified
problems should be handled.
C. Delete every observation containing a missing value.
D. Replace every extreme value with the mean.
**Answer: B**
**2.** A dataset contains employee ages recorded as 25, 31, 42, and
“thirty-five.” Which data-quality problem is MOST clearly
demonstrated?
A. Inconsistent data formatting
B. Sampling bias
C. Multicollinearity
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D. Overfitting
**Answer: A**
**3.** A researcher wants to determine whether two numerical
variables have a linear relationship before selecting an appropriate
analytical technique. Which visualization would generally be MOST
useful?
A. Pie chart
B. Scatterplot
C. Histogram of one variable only
D. Stacked bar chart
**Answer: B**
**4.** A dataset contains one variable representing annual income and
another representing years of education. The analyst observes that
higher education levels generally correspond to higher incomes. What
does this observation describe?
A. A possible association between the variables
B. Proof that education alone causes higher income
C. A categorical variable
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D. A data-entry error
**Answer: A**
**5.** A researcher calculates a correlation coefficient of approximately
+0.90 between two variables. Which interpretation is MOST
appropriate?
A. The variables have a strong positive linear association.
B. One variable definitely causes the other.
C. The variables have no relationship.
D. The variables must have identical values.
**Answer: A**
**6.** A correlation coefficient is approximately −0.85. What does this
result indicate?
A. A strong positive relationship
B. A weak positive relationship
C. A strong negative linear association
D. No measurable association
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**Answer: C**
**7.** An analyst finds a strong correlation between ice-cream sales
and the number of people visiting a swimming pool. Which conclusion
should be avoided without additional evidence?
A. The variables are associated.
B. Both variables may be influenced by another factor, such as
temperature.
C. Ice-cream sales necessarily cause people to visit swimming pools.
D. Correlation alone does not establish causation.
**Answer: C**
**8.** A dataset contains a variable with categories such as “Excellent,”
“Good,” “Fair,” and “Poor.” What type of variable is this?
A. Nominal categorical variable
B. Ordinal categorical variable
C. Continuous numerical variable
D. Ratio-scale variable
**Answer: B**
WGU D486 DFN1 Task 1 EXAM WITH COMPLETE 250 REAL
EXAM QUESTIONS AND CORRECT DETAILED ANSWERS
(VERIFIED ANSWERS) ALREADY GRADED A+
**1.** A data analyst is asked to evaluate a dataset before it is used to
support an organizational decision. The dataset contains missing values,
inconsistent formats, duplicate records, and several extreme
observations. What should the analyst do FIRST?
A. Build the final predictive model immediately.
B. Perform data-quality assessment and determine how the identified
problems should be handled.
C. Delete every observation containing a missing value.
D. Replace every extreme value with the mean.
**Answer: B**
**2.** A dataset contains employee ages recorded as 25, 31, 42, and
“thirty-five.” Which data-quality problem is MOST clearly
demonstrated?
A. Inconsistent data formatting
B. Sampling bias
C. Multicollinearity
,2|Page
D. Overfitting
**Answer: A**
**3.** A researcher wants to determine whether two numerical
variables have a linear relationship before selecting an appropriate
analytical technique. Which visualization would generally be MOST
useful?
A. Pie chart
B. Scatterplot
C. Histogram of one variable only
D. Stacked bar chart
**Answer: B**
**4.** A dataset contains one variable representing annual income and
another representing years of education. The analyst observes that
higher education levels generally correspond to higher incomes. What
does this observation describe?
A. A possible association between the variables
B. Proof that education alone causes higher income
C. A categorical variable
,3|Page
D. A data-entry error
**Answer: A**
**5.** A researcher calculates a correlation coefficient of approximately
+0.90 between two variables. Which interpretation is MOST
appropriate?
A. The variables have a strong positive linear association.
B. One variable definitely causes the other.
C. The variables have no relationship.
D. The variables must have identical values.
**Answer: A**
**6.** A correlation coefficient is approximately −0.85. What does this
result indicate?
A. A strong positive relationship
B. A weak positive relationship
C. A strong negative linear association
D. No measurable association
, 4|Page
**Answer: C**
**7.** An analyst finds a strong correlation between ice-cream sales
and the number of people visiting a swimming pool. Which conclusion
should be avoided without additional evidence?
A. The variables are associated.
B. Both variables may be influenced by another factor, such as
temperature.
C. Ice-cream sales necessarily cause people to visit swimming pools.
D. Correlation alone does not establish causation.
**Answer: C**
**8.** A dataset contains a variable with categories such as “Excellent,”
“Good,” “Fair,” and “Poor.” What type of variable is this?
A. Nominal categorical variable
B. Ordinal categorical variable
C. Continuous numerical variable
D. Ratio-scale variable
**Answer: B**
