Statistics Cheat Sheet 2026

The 30 highest-yield Statistics facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. What is a risk mitigation strategy in Statistics practice? → Implementing controls that reduce the likelihood or impact of identified risks
2. Which sampling method assigns each member of the population a unique number and selects individuals using a random number generator? → Simple random sampling
3. Which probability distribution is appropriate for modeling the number of successes in a fixed number of independent trials? → Binomial distribution
4. In multiple regression, what does multicollinearity refer to? → High correlation among predictor variables
5. What is the variance of the dataset {2, 4, 4, 4, 5, 5, 7, 9}? → 4
6. What is a one-tailed hypothesis test used for? → Testing for an effect in a specific direction
7. What is the effect of increasing the significance level (α) from 0.05 to 0.10 on a hypothesis test? → Increases the probability of a Type I error and raises power
8. The empirical rule states that approximately what percentage of data falls within 2 standard deviations of the mean in a normal distribution? → 95%
9. In the context of regression, what is overfitting? → A model that fits the training data too closely and performs poorly on new data
10. What is the primary purpose of conducting a pilot test before deploying a full survey? → To identify and correct flaws or ambiguities in the questionnaire
11. What is the first step in risk assessment for Statistics professionals? → Identifying potential hazards and vulnerabilities in the specific context
12. What is the law of large numbers? → As sample size increases, the sample mean converges to the population mean
13. When comparing two datasets, one with a standard deviation of 3 and another with a standard deviation of 9, what can be said about their variability? → The second dataset has three times the spread of the first
14. Which sampling approach is most susceptible to producing a biased, non-representative sample? → Convenience sampling
15. Which test is appropriate for comparing the means of two independent groups? → Two-sample t-test
16. What is the purpose of a cumulative frequency distribution? → To show the number of observations at or below each value
17. Which approach best demonstrates professional competency in Statistics practice? → Integrating continuing education, practical experience, and evidence-based decision making
18. In proportional stratified sampling, how is the number of individuals selected from each stratum determined? → In proportion to the stratum's relative size in the population
19. Post-survey weighting is applied primarily to: → Correct for over- or under-representation of certain groups relative to the population
20. Snowball sampling is most appropriate when the researcher is studying: → A rare or hard-to-reach population without an available sampling frame
21. In a symmetric bell-shaped distribution, which of the following is true? → Mean = Median = Mode
22. What does a frequency polygon display? → Distribution shape using connected midpoint frequencies
23. What characteristic defines the geometric distribution? → Number of trials until the first success in repeated Bernoulli trials
24. Why is evidence-based practice important in Statistics? → It integrates best available evidence with professional expertise for optimal outcomes
25. What does the standard error of the estimate (SEE) measure in regression? → The typical size of the prediction error (residual)
26. Why is documentation important in Statistics risk management? → It creates an audit trail, supports decision-making, and demonstrates due diligence
27. What is the primary value of case study analysis in Statistics training? → Developing critical thinking by applying theory to realistic professional scenarios
28. What is the role of professional journals in Statistics practice? → They disseminate current research, best practices, and professional developments
29. What is the coefficient of variation (CV) used for? → Comparing variability between datasets with different units or means
30. Which of the following is the correct range for the Pearson correlation coefficient r? → −1 to +1