MATH 225
Statistical Reasoning
Comprehensive Midterms Review (Qns &
Ans)
2025
1. Which statistical test is appropriate for comparing the means
of two independent groups?
- A) Chi-square test
- B) Paired t-test
- C) Independent t-test
- D) ANOVA
- ANS: C) Independent t-test
©/2025
, - Rationale: The independent t-test is used to compare the
means of two independent groups to determine if there is a
significant difference between them.
2. What is the primary purpose of conducting a power analysis
in a research study?
- A) To determine the statistical significance of the results
- B) To assess the reliability of the data
- C) To calculate the sample size needed to detect an effect
- D) To evaluate the validity of the measurement instruments
- ANS: C) To calculate the sample size needed to detect an
effect
- Rationale: Power analysis is conducted to calculate the
sample size required to detect a statistically significant effect in a
study, ensuring adequate study power.
Fill-in-the-Blank Questions
3. The __________ is the measure of central tendency that
represents the middle value of a data set when the values are
arranged in ascending or descending order.
- ANS: Median
- Rationale: The median is the measure of central tendency
that represents the middle value of a data set, providing a robust
measure of central location, especially for skewed distributions.
©/2025
,4. __________ is a statistical method used to examine the
relationship between two or more variables.
- ANS: Regression analysis
- Rationale: Regression analysis is a statistical method used
to examine the relationship between two or more variables,
helping to understand the impact of one or more independent
variables on a dependent variable.
True/False Questions
5. True or False: A p-value less than 0.05 typically indicates that
the results of a study are statistically significant.
- ANS: True
- Rationale: A p-value less than 0.05 is commonly used as the
threshold for statistical significance, suggesting that the observed
results are unlikely to have occurred by chance alone.
6. True or False: The null hypothesis states that there is a
significant effect or difference between groups.
- ANS: False
- Rationale: The null hypothesis states that there is no
significant effect or difference between groups, serving as the
default assumption that the study seeks to test against.
©/2025
, Multiple Response Questions
7. Which of the following are measures of variability in a data
set? (Select all that apply)
- A) Mean
- B) Standard deviation
- C) Interquartile range (IQR)
- D) Mode
- ANS: B) Standard deviation, C) Interquartile range (IQR)
- Rationale: Measures of variability include standard
deviation and interquartile range (IQR), which describe the spread
and dispersion of data. Mean and mode are measures of central
tendency, not variability.
8. Which of the following assumptions are required for
conducting a parametric test? (Select all that apply)
- A) The data are normally distributed
- B) The sample size is large
- C) The data are measured on at least an interval scale
- D) The data are nominal
- ANS: A) The data are normally distributed, C) The data are
measured on at least an interval scale
- Rationale: Parametric tests require that the data are
normally distributed and measured on at least an interval scale.
©/2025
Statistical Reasoning
Comprehensive Midterms Review (Qns &
Ans)
2025
1. Which statistical test is appropriate for comparing the means
of two independent groups?
- A) Chi-square test
- B) Paired t-test
- C) Independent t-test
- D) ANOVA
- ANS: C) Independent t-test
©/2025
, - Rationale: The independent t-test is used to compare the
means of two independent groups to determine if there is a
significant difference between them.
2. What is the primary purpose of conducting a power analysis
in a research study?
- A) To determine the statistical significance of the results
- B) To assess the reliability of the data
- C) To calculate the sample size needed to detect an effect
- D) To evaluate the validity of the measurement instruments
- ANS: C) To calculate the sample size needed to detect an
effect
- Rationale: Power analysis is conducted to calculate the
sample size required to detect a statistically significant effect in a
study, ensuring adequate study power.
Fill-in-the-Blank Questions
3. The __________ is the measure of central tendency that
represents the middle value of a data set when the values are
arranged in ascending or descending order.
- ANS: Median
- Rationale: The median is the measure of central tendency
that represents the middle value of a data set, providing a robust
measure of central location, especially for skewed distributions.
©/2025
,4. __________ is a statistical method used to examine the
relationship between two or more variables.
- ANS: Regression analysis
- Rationale: Regression analysis is a statistical method used
to examine the relationship between two or more variables,
helping to understand the impact of one or more independent
variables on a dependent variable.
True/False Questions
5. True or False: A p-value less than 0.05 typically indicates that
the results of a study are statistically significant.
- ANS: True
- Rationale: A p-value less than 0.05 is commonly used as the
threshold for statistical significance, suggesting that the observed
results are unlikely to have occurred by chance alone.
6. True or False: The null hypothesis states that there is a
significant effect or difference between groups.
- ANS: False
- Rationale: The null hypothesis states that there is no
significant effect or difference between groups, serving as the
default assumption that the study seeks to test against.
©/2025
, Multiple Response Questions
7. Which of the following are measures of variability in a data
set? (Select all that apply)
- A) Mean
- B) Standard deviation
- C) Interquartile range (IQR)
- D) Mode
- ANS: B) Standard deviation, C) Interquartile range (IQR)
- Rationale: Measures of variability include standard
deviation and interquartile range (IQR), which describe the spread
and dispersion of data. Mean and mode are measures of central
tendency, not variability.
8. Which of the following assumptions are required for
conducting a parametric test? (Select all that apply)
- A) The data are normally distributed
- B) The sample size is large
- C) The data are measured on at least an interval scale
- D) The data are nominal
- ANS: A) The data are normally distributed, C) The data are
measured on at least an interval scale
- Rationale: Parametric tests require that the data are
normally distributed and measured on at least an interval scale.
©/2025
