WGU C207 Data-Driven Decision Making Week
8 Final Exam Case Studies & Rationales
Practice Exam – Version 1
1. A hospital administrator wants to determine whether a new triage protocol has reduced average
wait times. Which statistical test is most appropriate?
A. Chi-square test
B. Paired t-test
C. Independent samples t-test
D. ANOVA
Correct Answer: C
Rationale: An independent samples t-test compares the means of two independent groups (wait
times before and after the new protocol). A paired t-test is used for matched or repeated
measures. Chi-square tests categorical data. ANOVA compares means of three or more groups.
2. A retail company wants to determine whether customer satisfaction scores differ across four store
locations. Which statistical test is most appropriate?
A. Paired t-test
B. Independent samples t-test
C. One-way ANOVA
D. Chi-square test
Correct Answer: C
Rationale: One-way ANOVA compares the means of three or more independent groups. A paired
t-test is used for matched pairs. An independent samples t-test compares two groups. Chi-
square tests categorical data.
3. A data analyst is examining the relationship between advertising spend and sales revenue. Which
statistical measure is most appropriate?
A. Chi-square test
B. Pearson correlation coefficient
C. t-test
D. ANOVA
,Correct Answer: B
Rationale: The Pearson correlation coefficient measures the strength and direction of the linear
relationship between two continuous variables. Chi-square tests categorical data. t-tests and
ANOVA compare means.
4. A company wants to predict sales based on advertising spend, price, and seasonality. Which
analytical technique is most appropriate?
A. Descriptive statistics
B. Multiple regression analysis
C. Chi-square test
D. t-test
Correct Answer: B
Rationale: Multiple regression analysis predicts a continuous dependent variable (sales) based
on multiple independent variables (advertising spend, price, seasonality). Descriptive statistics
summarize data. Chi-square and t-tests are used for different purposes.
5. Which of the following is an example of a null hypothesis?
A. There is a difference between the means of two groups.
B. There is no difference between the means of two groups.
C. There is a relationship between two variables.
D. There is an effect of the treatment.
Correct Answer: B
Rationale: The null hypothesis (H₀) states that there is no difference or no relationship between
variables. The alternative hypothesis (H₁) states that there is a difference or relationship.
6. A researcher sets the significance level at 0.05. What does this mean?
A. There is a 5% chance of accepting the null hypothesis when it is false.
B. There is a 5% chance of rejecting the null hypothesis when it is true.
C. There is a 95% chance of rejecting the null hypothesis.
D. There is a 95% chance of accepting the null hypothesis.
Correct Answer: B
Rationale: A significance level of 0.05 means there is a 5% chance of making a Type I error—
rejecting the null hypothesis when it is actually true. This is also known as the alpha level.
, 7. Which of the following is a Type II error?
A. Rejecting the null hypothesis when it is true
B. Failing to reject the null hypothesis when it is false
C. Accepting the alternative hypothesis when it is true
D. Rejecting the alternative hypothesis when it is false
Correct Answer: B
Rationale: A Type II error (beta) occurs when the researcher fails to reject the null hypothesis
when it is actually false. A Type I error (alpha) occurs when the null hypothesis is rejected when
it is true.
8. A p-value of 0.03 is obtained in a hypothesis test with a significance level of 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
Correct Answer: B
Rationale: Since the p-value (0.03) is less than the significance level (0.05), the null hypothesis is
rejected. There is sufficient evidence to support the alternative hypothesis.
9. Which of the following is a measure of central tendency?
A. Standard deviation
B. Variance
C. Mean
D. Range
Correct Answer: C
Rationale: The mean is a measure of central tendency. Standard deviation, variance, and range
are measures of dispersion (spread).
10. Which of the following is a measure of dispersion?
A. Median
B. Mode
C. Standard deviation
D. Mean
8 Final Exam Case Studies & Rationales
Practice Exam – Version 1
1. A hospital administrator wants to determine whether a new triage protocol has reduced average
wait times. Which statistical test is most appropriate?
A. Chi-square test
B. Paired t-test
C. Independent samples t-test
D. ANOVA
Correct Answer: C
Rationale: An independent samples t-test compares the means of two independent groups (wait
times before and after the new protocol). A paired t-test is used for matched or repeated
measures. Chi-square tests categorical data. ANOVA compares means of three or more groups.
2. A retail company wants to determine whether customer satisfaction scores differ across four store
locations. Which statistical test is most appropriate?
A. Paired t-test
B. Independent samples t-test
C. One-way ANOVA
D. Chi-square test
Correct Answer: C
Rationale: One-way ANOVA compares the means of three or more independent groups. A paired
t-test is used for matched pairs. An independent samples t-test compares two groups. Chi-
square tests categorical data.
3. A data analyst is examining the relationship between advertising spend and sales revenue. Which
statistical measure is most appropriate?
A. Chi-square test
B. Pearson correlation coefficient
C. t-test
D. ANOVA
,Correct Answer: B
Rationale: The Pearson correlation coefficient measures the strength and direction of the linear
relationship between two continuous variables. Chi-square tests categorical data. t-tests and
ANOVA compare means.
4. A company wants to predict sales based on advertising spend, price, and seasonality. Which
analytical technique is most appropriate?
A. Descriptive statistics
B. Multiple regression analysis
C. Chi-square test
D. t-test
Correct Answer: B
Rationale: Multiple regression analysis predicts a continuous dependent variable (sales) based
on multiple independent variables (advertising spend, price, seasonality). Descriptive statistics
summarize data. Chi-square and t-tests are used for different purposes.
5. Which of the following is an example of a null hypothesis?
A. There is a difference between the means of two groups.
B. There is no difference between the means of two groups.
C. There is a relationship between two variables.
D. There is an effect of the treatment.
Correct Answer: B
Rationale: The null hypothesis (H₀) states that there is no difference or no relationship between
variables. The alternative hypothesis (H₁) states that there is a difference or relationship.
6. A researcher sets the significance level at 0.05. What does this mean?
A. There is a 5% chance of accepting the null hypothesis when it is false.
B. There is a 5% chance of rejecting the null hypothesis when it is true.
C. There is a 95% chance of rejecting the null hypothesis.
D. There is a 95% chance of accepting the null hypothesis.
Correct Answer: B
Rationale: A significance level of 0.05 means there is a 5% chance of making a Type I error—
rejecting the null hypothesis when it is actually true. This is also known as the alpha level.
, 7. Which of the following is a Type II error?
A. Rejecting the null hypothesis when it is true
B. Failing to reject the null hypothesis when it is false
C. Accepting the alternative hypothesis when it is true
D. Rejecting the alternative hypothesis when it is false
Correct Answer: B
Rationale: A Type II error (beta) occurs when the researcher fails to reject the null hypothesis
when it is actually false. A Type I error (alpha) occurs when the null hypothesis is rejected when
it is true.
8. A p-value of 0.03 is obtained in a hypothesis test with a significance level of 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
Correct Answer: B
Rationale: Since the p-value (0.03) is less than the significance level (0.05), the null hypothesis is
rejected. There is sufficient evidence to support the alternative hypothesis.
9. Which of the following is a measure of central tendency?
A. Standard deviation
B. Variance
C. Mean
D. Range
Correct Answer: C
Rationale: The mean is a measure of central tendency. Standard deviation, variance, and range
are measures of dispersion (spread).
10. Which of the following is a measure of dispersion?
A. Median
B. Mode
C. Standard deviation
D. Mean
