Statistics I
Lezione I – 09/09/2025
Introduzione
Lezione II – 10/09/2025
Chapter 1 – Using graphs to represent data
We don’t live in a deterministic world, so we’ll need statistics because we’re
sorrounded by uncertainty.
Key definitions
Population: complete set of all items of interest.
N represents population size.
Sample: observed subset of a population.
n represents sample size.
It is used by statistics because of time, costs, and it’s better manage small
numbers of objecte than biggers.
Parameter: specific characteristic of a population.
Statistic: specific characteristic of a sample.
Two branches of statistics:
Descriptive statistics: graphical and numerical procedures to to summarize
and process data.
Inferential statistics: using the data to make predictions, forecasts and
estimates to help decision making. (with a controllable degree of uncertainty or
error).
Median value splits in two parts, 50% has more and the 50% has less.
Average value in not the median value.
Modal value is the one that indicates the majority.
