Statistics for Managers Using Microsoft Excel, 9th Edition -
2025/2026 Study Guide
Chapter 1: Introduction and Data Collection
1. What is the difference between descriptive and inferential statistics?
o ANSWER ✓ Descriptive statistics summarize and present data (e.g., mean, charts).
Inferential statistics make predictions or generalizations about a population based on a
sample.
2. Define a population and a sample.
o ANSWER ✓ A population is the entire group of interest. A sample is a subset selected
from the population.
3. What are the two main types of data?
o ANSWER ✓ Categorical (qualitative, e.g., product type) and Numerical (quantitative, e.g.,
sales revenue).
4. What is the difference between discrete and continuous numerical data?
o ANSWER ✓ Discrete data are countable and finite (e.g., number of customers).
Continuous data are measurable and infinite within a range (e.g., time, weight).
5. List the four basic sampling methods.
o ANSWER ✓ Simple Random, Systematic, Stratified, and Cluster sampling.
Chapter 2: Organizing and Visualizing Data
6. When should you use a bar chart versus a pie chart?
- ANSWER ✓ Use a bar chart to compare frequencies across categories. Use a pie chart
to show proportions or percentages of a whole for a limited number of categories.
7. What is the purpose of a frequency distribution?
o ANSWER ✓ To summarize data by grouping observations into classes and showing the
count or proportion in each class.
8. Describe a Pareto chart and its managerial use.
o ANSWER ✓ It is a bar chart sorted in descending frequency, combined with a
cumulative percentage line. It is used to identify the "vital few" from the "trivial many"
(e.g., main causes of customer complaints).
9. When is a histogram used, and what does its shape reveal?
, o ANSWER ✓ A histogram visualizes the distribution of continuous numerical data. Its
shape (symmetric, skewed left/right, bimodal) reveals patterns like central tendency,
spread, and potential outliers.
10. What does a scatter plot illustrate?
o ANSWER ✓ It illustrates the relationship or correlation between two numerical variables.
Chapter 3: Numerical Descriptive Measures
11. Define the mean, median, and mode. Which is most affected by outliers?
- ANSWER ✓ Mean is the average. Median is the middle value. Mode is the most
frequent value. The mean is most affected by outliers.
12. When is the median preferred over the mean as a measure of central tendency?
o ANSWER ✓ The median is preferred when data are skewed or contain significant
outliers (e.g., income, house prices).
13. What does the standard deviation measure?
o ANSWER ✓ It measures the average variation or dispersion of data points around the
mean.
14. Interpret a standard deviation.
o ANSWER ✓ A larger standard deviation indicates greater variability in the data. A
smaller one indicates data points are clustered closer to the mean.
15. What does the coefficient of variation (CV) allow you to compare?
o ANSWER ✓ The CV allows you to compare the relative variability of datasets with
different units or vastly different means.
16. What do the Z-score and the Empirical Rule describe?
o ANSWER ✓ A Z-score measures how many standard deviations a point is from the
mean. The Empirical Rule states that for a normal distribution, ~68%, ~95%, and ~99.7%
of data lie within 1, 2, and 3 standard deviations of the mean, respectively.
17. What does the correlation coefficient (r) measure?
o ANSWER ✓ It measures the strength and direction of the linear relationship between
two numerical variables (-1 to +1).
Chapter 4: Basic Probability
18. Define the probability of an event.
- ANSWER ✓ It is a number between 0 and 1 (inclusive) that represents the likelihood
the event will occur.
19. What is the difference between simple, joint, and conditional probability?
2025/2026 Study Guide
Chapter 1: Introduction and Data Collection
1. What is the difference between descriptive and inferential statistics?
o ANSWER ✓ Descriptive statistics summarize and present data (e.g., mean, charts).
Inferential statistics make predictions or generalizations about a population based on a
sample.
2. Define a population and a sample.
o ANSWER ✓ A population is the entire group of interest. A sample is a subset selected
from the population.
3. What are the two main types of data?
o ANSWER ✓ Categorical (qualitative, e.g., product type) and Numerical (quantitative, e.g.,
sales revenue).
4. What is the difference between discrete and continuous numerical data?
o ANSWER ✓ Discrete data are countable and finite (e.g., number of customers).
Continuous data are measurable and infinite within a range (e.g., time, weight).
5. List the four basic sampling methods.
o ANSWER ✓ Simple Random, Systematic, Stratified, and Cluster sampling.
Chapter 2: Organizing and Visualizing Data
6. When should you use a bar chart versus a pie chart?
- ANSWER ✓ Use a bar chart to compare frequencies across categories. Use a pie chart
to show proportions or percentages of a whole for a limited number of categories.
7. What is the purpose of a frequency distribution?
o ANSWER ✓ To summarize data by grouping observations into classes and showing the
count or proportion in each class.
8. Describe a Pareto chart and its managerial use.
o ANSWER ✓ It is a bar chart sorted in descending frequency, combined with a
cumulative percentage line. It is used to identify the "vital few" from the "trivial many"
(e.g., main causes of customer complaints).
9. When is a histogram used, and what does its shape reveal?
, o ANSWER ✓ A histogram visualizes the distribution of continuous numerical data. Its
shape (symmetric, skewed left/right, bimodal) reveals patterns like central tendency,
spread, and potential outliers.
10. What does a scatter plot illustrate?
o ANSWER ✓ It illustrates the relationship or correlation between two numerical variables.
Chapter 3: Numerical Descriptive Measures
11. Define the mean, median, and mode. Which is most affected by outliers?
- ANSWER ✓ Mean is the average. Median is the middle value. Mode is the most
frequent value. The mean is most affected by outliers.
12. When is the median preferred over the mean as a measure of central tendency?
o ANSWER ✓ The median is preferred when data are skewed or contain significant
outliers (e.g., income, house prices).
13. What does the standard deviation measure?
o ANSWER ✓ It measures the average variation or dispersion of data points around the
mean.
14. Interpret a standard deviation.
o ANSWER ✓ A larger standard deviation indicates greater variability in the data. A
smaller one indicates data points are clustered closer to the mean.
15. What does the coefficient of variation (CV) allow you to compare?
o ANSWER ✓ The CV allows you to compare the relative variability of datasets with
different units or vastly different means.
16. What do the Z-score and the Empirical Rule describe?
o ANSWER ✓ A Z-score measures how many standard deviations a point is from the
mean. The Empirical Rule states that for a normal distribution, ~68%, ~95%, and ~99.7%
of data lie within 1, 2, and 3 standard deviations of the mean, respectively.
17. What does the correlation coefficient (r) measure?
o ANSWER ✓ It measures the strength and direction of the linear relationship between
two numerical variables (-1 to +1).
Chapter 4: Basic Probability
18. Define the probability of an event.
- ANSWER ✓ It is a number between 0 and 1 (inclusive) that represents the likelihood
the event will occur.
19. What is the difference between simple, joint, and conditional probability?
