Visual displays of data

Seite 1

Concepts:

Population: of the items of an interest

Sample: a portion of the total population

Raw data: new information obtained that wasn´t organized yet

Quantitative data: # of items in a set

Qualitative data: Quality items of a set

Frequency distribution:

Definition: element that helps to tell how many times a single item repeats in the population

Relative frequency: Absolute frequency divided by the number of total raw data (fi/n)

Example:

Seite 2

Frequency polygon (line graph): he same as the graph but change it to plot points and join them. A general line graph.

Stem and leaf display: A method of easier counting raw data by making little sections or divisions (stem) and then put the information that gets in in the determined stem (leaves).

Histogram: Graphs but the bars are places next to each other. Used normally in large samples or continious data.

Circle graphs: pie chart that shows each percentage of each element.