Statistics
Is a branch of science that deals with the collection, organization, presentation, analytics, and interpretation of data.
categories
1. Descriptive
2. Differential
3. Indeferential
Descriptive - summary values and presentations that give some information about data eg the median height.
In deferential - summary values are calculated from the sample in order to make conclusions about the target.
Types of variables
- Qualitative variables
Their values fall into groups or categories
also known as categorical
Divided into 2 classes :
- Nominal Variables
- ordinal variables
Nominal
Are names with no natural ordering eg gender
Ordinal
Variables whose categories have a natural ordering.
- Quantitatve variables
Numeric variables are divided into 2 classes :
- Discrete
- Continuous
Discrete variables can only assume certain values and there are gaps between them eg the number of calls in a day.
Continuous variables Can assume various variables in a certain range eg Length of a telephone call.