Chapter 2

• 2-1 Introduction

• 2-2 Organizing Data

• 2-3 Histograms, Frequency Polygons, and Ogives

• 2-4 Other types of Graphs

• 2-5 Summary

2-3 Histograms, Frequency Polygons, and Ogives (cont)

• Distribution shapes– Bell- shaped– Uniform– J-shaped– Reverse j-shaped– Right-skewed– Left-skewed– Bimodal u-shaped

Bell Shaped

Uniform

J Shaped

Bimodal u-shaped

Skewed

2-3 Histograms, Frequency Polygons, and Ogives (cont)

• Histogram

• Frequency polygon– Cumulative frequency

• Ogive

• Relative frequency graph

Frequency Polygon

Ogive

Relative Frequency

2-4 Other Types of Graphs

• Pareto charts

• Time series graphs

• Pie charts

2-4 Other Types of Graphs (Cont)

• Pareto charts– Represents frequency distributions for a

categorical variable– Frequencies are displayed by heights from

least to greatest

Pareto

•  power law probability distribution that is used in description of social, scientific, geophysical, actuarial, and many other types of observable phenomena.

Pareto

2-4 Other Types of Graphs (Cont)

• Time series graphs– Represent data that occur over a specific

period of time

Time series

2-4 Other Types of Graphs (Cont)

• Pie Graph– A circle that is divided into sections or wedges

according to the percentage of frequencies in each category of the distribution.

Pie Charts