Interview and Exam Prep: Key Statistics Questions
You have now completed the full Statistics course.
This final lesson is designed to help you:
- Revise core statistical concepts
- Prepare for interviews and exams
- Build confidence in explaining statistics clearly
Focus here is not memorization, but understanding and communication.
How Statistics Questions Are Asked
In interviews and exams, statistics questions usually test:
- Conceptual understanding
- Interpretation of results
- Choosing the correct test
- Explaining results in simple language
Core Concept Review
- Descriptive vs Inferential statistics
- Mean, median, mode, variance, standard deviation
- Probability and distributions
- Confidence intervals and hypothesis testing
- Correlation vs regression
- Chi-square tests
- ANOVA and nonparametric tests
Common Interview Questions
Question 1:
What is the difference between correlation and regression?
Correlation measures the strength of a relationship. Regression models the relationship and allows prediction.
Question 2:
What does a p-value represent?
The probability of observing the data assuming the null hypothesis is true.
Question 3:
When would you use a nonparametric test?
When data is not normally distributed, contains outliers, or is measured on an ordinal scale.
Exam-Oriented Questions
Question:
Why is ANOVA preferred over multiple t tests?
Because multiple t tests increase the chance of false positives. ANOVA controls the overall error rate.
Question:
What does R-squared measure?
The proportion of variation in the dependent variable explained by the model.
Choosing the Right Test (Very Important)
| Situation | Recommended Test |
|---|---|
| Compare two means | t test |
| Compare proportions | Z test |
| Relationship between categorical variables | Chi-square test |
| Compare 3+ means | ANOVA |
| Non-normal or ordinal data | Nonparametric test |
Mini Practice
You are given customer data with:
- Age (numerical)
- Subscription type (categorical)
- Monthly spending (numerical)
Which statistical methods would you use to:
- Compare spending across subscription types?
- Predict spending?
ANOVA to compare spending across groups. Regression to predict spending.
Final Advice for Interviews
- Explain concepts in simple language
- Always state assumptions
- Interpret results in context
- Never say “because software said so”
🎉 Course Completion
You have successfully completed the Statistics Course.
Click the button below to celebrate your achievement.
What’s Next?
You can now move forward to advanced Scala frameworks, big data processing with Spark, or your next Dataplexa module.