Lesson Three: Descriptive Statistics

Descriptive statistics are a way of summarizing data or letting one number stand for a group of numbers.

There are three ways we can summarize and present data.

Presenting Data.

Tabular representation of data - we can summarize data by making a table of the data. In statistics we call these tables frequency distributions and in this lesson we will look at four different types of frequency distributions.

Simple frequency distribution (or it can be just called a frequency distribution).

Cummulative frequency distribution.

Grouped frequency distribution.

Cummulative grouped frequency distribution.

Graphical representation of data - we can make a graph of the data. In lesson 4 we will consider four types of graphs.

FREE Tool to Create Graphic Display
bar graph
histogram
frequency polygon
scatter diagram

Pie Chart

Ogive (ō'jīv')

Numerical representation of data - we can use a single number to represent many numbers. We will discuss three types of numerical representation of data in lessons 5, 6, and 8.

Measures of central tendency.

Measures of variability.

Frequency distribution