Zusammenfassung der Ressource
Frequency distributions &
data in tables and graphs
- most basic descriptive statistic, and are a method of imposing some
structure on numerical data.
- systematic way of arranging numeric values from the lowest to the highest,
- together with a count or percentage of the number of times each value occurred.
- reflects a simple count of how frequently each value of the variable occurred.
- Symmetric
- shape indicates that if we were to fold the
graph in half, the two halves of the frequency
polygon would be superimposed
- presented in the previous frequency histogram
- polygon describes an approximately symmetric distribution (ie it is
slightly skewed).
- Skewed
- peak of the graph is off-centre, with one tail longer than the other
- +ve
- longer tail is pointed towards
the right
- -ve
- longer tail points towards the left