Statistical Analysis for Business Economics: Summer 2010 Statistical Analysis for Business Economics: Spring 2011 STATISTICAL ANALYSIS FOR BUS ECON

Statistical Analysis for Business & Economics: Summer 2010 Statistical Analysis for Business & Economics: Spring 2011

STATISTICAL ANALYSIS FOR BUS & ECON

Chapter 2: Tables and Graphs

E370 Spring 2016


Objectives

•Be able to distinguish different kinds and types of data•Be able to choose the best graphical presentations for different kinds of data•Be able to use Excel to draw them

Statistical Analysis for Business & Economics: Spring 2016


Information contained in data is valuable

A survey asks students to identify which laptop brand they have purchased. The responses are1. HP2. Toshiba3. Apple4. Dell5. Other


Response3343543453345254234433342

Visualize it!


Data Data Types Appropriate Graphs

Numerical

Discrete (e.g. number of kids)Continuous (e.g. Length of a song)

Histogram(no gaps between columns)

Frequency Polygon

Ogive (cumulative frequencies)

Categorical

Nominal (e.g. eyes color: blue/black/brown)Ordinal (e.g. Restaurant rankings: very good/good/fine/bad)

Pie ChartColumn/Bar chartPareto Diagram (has the order)

Theory



Graphical Techniques for Numerical Data


• Decide the number of classes.• Decide the class intervals and set class

limits• Enter the bin range (right open

intervals)• Close the column gaps.




• A line version of the histogram• Plotted using class midpoints• Best way to represent several variables on

the same axes.• The look of the data is easily influenced by

the classes selected. That is, it shares the same problems as histogram




• A line version of cumulative frequencies• Plotted using upper class limits and

frequencies • Non-decreasing graph, always begins at

(0,0)


Graphical Techniques for Categorical Data

8

HP16%

Dell32%Mac

38%

Sony10%

other4%

Pie chart for PC Purchase by Brand

HPDellMacSonyother


• Good for relative comparisons among categories.• If there is a large number of categories or frequencies

are small, it may not be informative.



9

HP

Dell

Mac

Sony

other

0 2 4 6 8 10 12 14 16 18 20

Bar chart for PC Purchase by Brand

Frequency


• Bar chart is also used for relative comparisons among categories.

• It is useful when there is a large number of categories or frequencies are small.



10Statistical Analysis for Business & Economics: Spring 2016

R Ctr R Door RB Post R Rdr R Fender

L Ctr RA Post

LA Post L Door Roof Other0123

456789

Pareto Diagram

• Only useful on non-numerical data.• If there are lots of categories, it rapidly pinpoints the

important groups.• Designed to separate the important few from the

trivial many


If you are doing a presentation to Apple


What graph to include? What information to highlight?

Apple Dell Other Toshiba HP0

5

10

15

20

25

Pareto Diagram

1. HP 2. Toshiba 3. Apple 4. Dell 5. Other0

5

10

15

20

Column Chart1. HP

2. Toshiba

3. Apple

4. Dell

5. Other

Pie Chart

1. HP

2. Toshiba

3. Apple

4. Dell

5. Other

0 5 10 15 20 25 30

Bar Chart

Documents

Statistical Analysis for Business Economics: Summer 2010 Statistical Analysis for Business Economics: Spring 2011 STATISTICAL ANALYSIS FOR BUS ECON