STA1501 · DESCRIPTIVE STATISTICS AND PROBABILITY
Complete Module
Cheatsheet
All eleven chapters’ formula cheatsheets combined into a single
volume, in order, for fast exam revision.
Chapter 1 — What is Statistics?
Chapter 2 — Graphical Descriptive Techniques
Chapter 3 — Numerical Descriptive Techniques
Chapter 4 — Data Collection and Sampling
Chapter 5 — Basic Probability
Chapter 6 — Random Variables & Discrete Distributions
Chapter 7 — Continuous Probability Distributions
Chapter 8 — Sampling Distributions
Chapter 9 — Introduction to Estimation
Chapter 10 — Introduction to Hypothesis Testing
Chapter 11 — Inference About a Population
CHEATSHEET · ALL CHAPTERS
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,AMP STUDY NOTES
STA1501 · DESCRIPTIVE STATISTICS AND PROBABILITY
Chapter 1
Cheatsheet
What is Statistics? — core definitions and a fast classification guide
for exam revision.
CHEATSHEET · CHAPTER 1
Independent study material. Independently authored revision aid, not affiliated with, endorsed by, or sourced
from UNISA or any official assessment body. © AMP Study Notes.
, AMP Study Notes — STA1501 — Chapter 1 Cheatsheet
Chapter 1 Cheatsheet: What is Statistics?
Core Definitions
POPULATION VS SAMPLE
Population: all items of interest. Sample: a subset actually collected. Parameter: descriptive measure of the population
( ). Statistic: descriptive measure of the sample ( ).
DESCRIPTIVE VS INFERENTIAL
Descriptive: summarises data you have, no claim beyond it. Inferential: uses a sample statistic to draw a conclusion
about the population parameter.
Data Type Decision Guide
ASK YOURSELF… ANSWER DATA TYPE
Are the values categories with no natural order? Yes Nominal (qualitative / categorical)
Are the values categories that do have a natural order, but gaps Yes Ordinal
between them aren't a consistent numerical difference?
Are the values real numbers where a gap between two values means Yes Interval (quantitative / numerical —
something consistent (e.g. R100 is always R100)? ratio data included)
Fast Examples
VARIABLE TYPE
Marital status, province, brand of car Nominal
Course rating (poor…excellent), military rank, exam grade (A/B/C/D/F) Ordinal
Income, height, weight, exam mark out of 100, temperature Interval
Common Pitfalls (One Line Each)
• A numeric code (1, 2, 3…) doesn't make data interval — a - satisfaction rating is still ordinal.
• A value computed from a sample is a statistic, not a parameter, even if it's used to estimate one.
• Ratio data (has a true zero) is not a separate category here — it's classified as interval.
Page 2 of 2
, AMP STUDY NOTES
STA1501 · DESCRIPTIVE STATISTICS AND PROBABILITY
Chapter 2
Cheatsheet
Graphical Descriptive Techniques — core formulas and a fast build
guide for exam revision.
CHEATSHEET · CHAPTER 2
Independent study material. Independently authored revision aid, not affiliated with, endorsed by, or sourced
from UNISA or any official assessment body. © AMP Study Notes.