文档介绍：Exploring Marketing Research Chapter 17:Determining Sample Size
Exploring Marketing
Research
William G3>. Zikmund
Chapter 17:
Determining Sample Size
What does Statistics Mean?
Descriptive Statistics
Number of People
Trends in Employment
Data
Inferential Statistics
Make an inference about a population from a sample
Population Parameter Versus Sample Statistics
*Copyright ? 2000 by Harcourt, Inc. All rights reserved.
Population Parameter
Variables in a population
Measured characteristics of a population
Greek lower-case letters as notation
Sample Statistics
Variables in a sample
puted from data
English letters for notation
Making Data Usable
Frequency Distributions
Proportions
Central Tendency
Mean
Median
Mode
Measures of Dispersion
Frequency Distribution of Deposits
Frequency (number of
people making deposits
Amount in each range)
less than $3,000 499
$3,000 - $4,999 530
$5,000 - $9,999 562
$10,000 - $14,999 718
$15,000 or more 811
3,120
Amount Percent
less than $3,000 16
$3,000 - $4,999 17
$5,000 - $9,999 18
$10,000 - $14,999 23
$15,000 or more 26
100
Percentage Distribution of Amounts of Deposits
Amount Probability
less than $3,000 .16
$3,000 - $4,999 .17
$5,000 - $9,999 .18
$10,000 - $14,999 .23
$15,000 or more .26
Probability Distribution of Amounts of Deposits
Measures of Central Tendency
Mean - Arithmetic Average
?, population; , sample
Median - Midpoint of the Distribution
Mode - the Value that occurs most often
Population Mean
*Copyright ? 2000 by Harcourt, Inc. All rights reserved.
Sample Mean
*Copyright ? 2000 by Harcourt, Inc. All rights reserved.
Number of Sales Calls Per Day by Salespersons
Number of
Salesperson Sales calls
Mike 4
Patty 3
Billie 2
Bob 5
John 3
Frank 3
Chuck 1
Samantha 5
26
Sales for Products A and B, Both Average 200
Product A Product B
196 150
198 160
199 176
199 181
200 192
200 200
200 201
201 202
201 213
201 224
202 240
202 261
M