This document discusses key concepts in statistics including:
- The limitations of statistics such as not dealing with individuals directly, statistical laws not being exact, and potential for misuse.
- Definitions of secondary data, which is data collected for other purposes, and sources of secondary data such as internal/external and public sources.
- Descriptive statistics which analyze and represent previously collected data through measures like frequency, range, mean, mode, and standard deviation.
- Inferential statistics which use probability, hypothesis testing, correlation, and regression to analyze samples and make inferences about populations.