文档介绍：Chap 2-1
Business Statistics:
A Decision-Making Approach
Chapter 2 Graphs, Charts, and Tables – Describing Your Data
Chap 2-2
Chapter Goals
pleting this chapter, you should be able to:
Construct a frequency distribution both manually and with puter
Construct and interpret a histogram
Create and interpret bar charts, pie charts, and stem-and-leaf diagrams
Present and interpret data in line charts and scatter diagrams
Chap 2-3
Frequency Distributions(频数分布)
What is a Frequency Distribution?
A frequency distribution is a list or a table …
containing the values of a variable (or a set of ranges within which the data fall) ...
and the corresponding frequencies with which each value occurs (or frequencies with which data fall within each range)
Chap 2-4
Why Use Frequency Distributions?
A frequency distribution is a way to summarize data
The distribution condenses the raw data into a more useful form...
and allows for a quick visual interpretation of the data
Chap 2-5
Frequency Distribution: Discrete Data
Discrete data: possible values are countable
Example: An advertiser asks 200 customers how many days per week they read the daily newspaper.
Number of days read
Frequency
0
44
1
24
2
18
3
16
4
20
5
22
6
26
7
30
Total
200
Chap 2-6
Relative Frequency(相对频数)
Relative Frequency: What proportion is in each category?
Number of days read
Frequency
Relative
Frequency
0
44
.22
1
24
.12
2
18
.09
3
16
.08
4
20
.10
5
22
.11
6
26
.13
7
30
.15
Total
200
22% of the people in the sample report that they read the newspaper 0 days per week
Chap 2-7
Frequency Distribution: Continuous Data
Continuous Data: may take on any value in some interval
Example: A manufacturer of insulation randomly selects 20 winter days and records the daily high temperature
24, 35, 17, 21, 24, 37, 26, 46, 58, 30,
32, 13, 12, 38, 41, 43, 44, 27, 53, 27
(Temperature is a continuous variable because it could
be measured to any deg