# Lecture 5: Describing data (part 1)

September 20, 2022 (3rd week of classes)**Read and watch everything**

**Describing data via summary statistics**

Samples and populations are often made of lots of individual (observational) units and their associated information (observations, variables).

We need to be able to describe samples by summary statistics (mean, median, variance, etc) so that these summaries can serve as an estimate of the same summaries for their statistical populations.

Mode, Median, Mean, Range, and Standard Deviation (1.3), by Simple Learning Pro

**Lecture**

Slides:

Download revised lecture: 3 slides per page and outline

Download revised lecture: 1 slide per page

Videos:

**part 1:** goals of describing data, summary statistics,
location versus spread statistics, mean, variance &
standard deviation, rounding summary statistics for presentation purposes.

**part 2:** median, relating symmetry of frequency distributions to means and medians.