Class Notes
(808,753)

Canada
(493,377)

McMaster University
(38,362)

Statistics
(433)

STATS 2B03
(176)

Aaron Childs
(174)

Lecture

# Descriptive statistics.docx

Unlock Document

McMaster University

Statistics

STATS 2B03

Aaron Childs

Fall

Description

September 11 , 2012
STATS 2B03: Statistical Methods for Science
Descriptive Statistics (1)
Organizing Data
- Example: 2.8, 2.9, 3.0, 3.2, 5.4, 6.7, 6.9
- Leaf unit = 0.1
- In brackets you put the median
2 2 8, 9
(2) 3 0, 2
3 4
3 5 4
2 6 7, 9
Measures of Central Tendency
- the average of a sample, X , 1 ,…2 X isncalled the sample mean (or just the
mean) and I denoted by X , i.barX bar= (X1+ X +2… + X )/n = Σ x i=1in
- the average of the population X , X1, …2 X isNcalled the population mean and
is denoted by μ, i.e. μ = N Σ i=1/N X i
- note that N is the population size
- the mode of a data set is the value that occurs most often
e.g. 7, 8, 8, 8, 9, 9, 10, mode=8
e.g. 7, 8, 8, 8, 9, 9, 9, 10, 10, 11, two modes: 8 and 9
- in a grouped data set the modal class is the group with the largest frequency
e.g. grouping and frequency table: modal class would be the group
with the highest frequency which in this c

More
Less
Related notes for STATS 2B03