BU.920.621
Data Science (Statistics)
LATEST EXAM READINESS
GUIDE
Q&S
©2024/2025
,1. Which statistical test is most appropriate to compare
mean sales before and after a new marketing campaign?
- A) Chi-square test
- B) Paired t-test
- C) ANOVA
- D) Wilcoxon signed-rank test
Answer: B) Paired t-test
Rationale: The paired t-test is used to compare the
means of two related groups, like the same group's sales
before and after a marketing campaign.
2. What is the primary purpose of using a bootstrap
method in statistical analysis?
- A) To parameterize a model
- B) To estimate the distribution of a statistic
- C) To visualize data
- D) To determine causality
Answer: B) To estimate the distribution of a statistic
Rationale: Bootstrapping is used for estimating the
sampling distribution of a statistic by resampling with
replacement.
3. If the p-value of a test is 0.04 after analyzing the
relationship between two variables, what conclusion can be
drawn at the 0.05 significance level?
- A) Fail to reject the null hypothesis
- B) Reject the null hypothesis
- C) Increase the sample size
- D) The test is inconclusive
Answer: B) Reject the null hypothesis
Rationale: Since the p-value is less than 0.05, it provides
©2024/2025
, enough statistical evidence to reject the null hypothesis.
4. Which measure is commonly used to determine the
effectiveness of a linear regression model?
- A) Mean
- B) Median
- C) R-squared
- D) Mode
Answer: C) R-squared
Rationale: R-squared indicates the proportion of the
variance in the dependent variable that is predictable from
the independent variable(s).
5. Which concept explains the risk of falsely identifying a
pattern in data visualization due to testing multiple
hypotheses?
- A) Overfitting
- B) Simpson's Paradox
- C) P-hacking
- D) Type II error
Answer: C) P-hacking
Rationale: P-hacking involves manipulating data and
analytical methods until non-significant results become
significant, thus identifying patterns that do not exist.
### Fill-in-the-Blank
6. The central limit theorem states that the distribution of
sample means approaches a __________ distribution as
the sample size increases, regardless of the shape of the
population distribution.
Answer: normal
Rationale: The central limit theorem states that the mean
©2024/2025
Data Science (Statistics)
LATEST EXAM READINESS
GUIDE
Q&S
©2024/2025
,1. Which statistical test is most appropriate to compare
mean sales before and after a new marketing campaign?
- A) Chi-square test
- B) Paired t-test
- C) ANOVA
- D) Wilcoxon signed-rank test
Answer: B) Paired t-test
Rationale: The paired t-test is used to compare the
means of two related groups, like the same group's sales
before and after a marketing campaign.
2. What is the primary purpose of using a bootstrap
method in statistical analysis?
- A) To parameterize a model
- B) To estimate the distribution of a statistic
- C) To visualize data
- D) To determine causality
Answer: B) To estimate the distribution of a statistic
Rationale: Bootstrapping is used for estimating the
sampling distribution of a statistic by resampling with
replacement.
3. If the p-value of a test is 0.04 after analyzing the
relationship between two variables, what conclusion can be
drawn at the 0.05 significance level?
- A) Fail to reject the null hypothesis
- B) Reject the null hypothesis
- C) Increase the sample size
- D) The test is inconclusive
Answer: B) Reject the null hypothesis
Rationale: Since the p-value is less than 0.05, it provides
©2024/2025
, enough statistical evidence to reject the null hypothesis.
4. Which measure is commonly used to determine the
effectiveness of a linear regression model?
- A) Mean
- B) Median
- C) R-squared
- D) Mode
Answer: C) R-squared
Rationale: R-squared indicates the proportion of the
variance in the dependent variable that is predictable from
the independent variable(s).
5. Which concept explains the risk of falsely identifying a
pattern in data visualization due to testing multiple
hypotheses?
- A) Overfitting
- B) Simpson's Paradox
- C) P-hacking
- D) Type II error
Answer: C) P-hacking
Rationale: P-hacking involves manipulating data and
analytical methods until non-significant results become
significant, thus identifying patterns that do not exist.
### Fill-in-the-Blank
6. The central limit theorem states that the distribution of
sample means approaches a __________ distribution as
the sample size increases, regardless of the shape of the
population distribution.
Answer: normal
Rationale: The central limit theorem states that the mean
©2024/2025
