Part I actually
Chapter a couple of
Data Types, Data Screen and
Brief summary Statistics
one particular
Introduction
• Descriptive Statistics vs . Inferential Statistics
•
Descriptive Statistics - Data summarization
•
Inferential Stats - Make use of sample info to make
inferences about a human population
parameter.
•
Population: the gathering of objects upon which
measurements could be used.
•
Test: a subsection, subdivision, subgroup, subcategory, subclass of the population.
• Variable is the measurable characteristic of the
entity.
a couple of
Types of Data
• Quantitative or Qualitative?
•
Quantitative: presented as numbers allowing
arithmetic
•
•
•
Interest rate
Temperatures
Qualitative (categorical): everything else
•
Country of birth
•
Supplier
3
Types of Data
• Univariate or Multivariate?
•
Univariate: one truth for each target in a dataset (" one particular
column in a spreadsheet”)
•
Multivariate: several facts for each and every object in a
dataset (" many columns in a spreadsheet”)
4
Types of Data
• Discrete or perhaps Continuous?
•
Discrete: measured
•
•
•
Automobiles sold
Volume of children
Constant: measured (always allow " in-between”
values)
•
•
•
Gallons of essential oil sold
Temp
What about grow older? Money?
five
Types of Data
• Ordinal Data
•
Definition: " Qualitative data that has an ordering”
•
Example – Likert Level:
disagree firmly don't agree fairly neutral acknowledge agree strongly •
Often " measure” with numbers:
you = don't agree strongly
2 = differ
a few = agree strongly
6
Types of Data
• Period Series or perhaps Cross-Sectional?
•
Time series: when period sequencing is very important
•
•
•
ALL OF US historical pumpiing rates
A baby's weight
Cross-sectional: data are contemporaneous, all
accumulated at about the same time frame
•
2005 inflation costs for several countries
•
Excess weight at birth
several
The Distribution of Ideals of a Variable
(Graphical Procedures)
Frequency Distribution
What is a Frequency Distribution?
• A regularity distribution is known as a list or a table …
• that contains the principles of a variable (or a couple of
ranges within just which the info fall)...
• and the corresponding frequencies with which
each benefit occurs (or frequencies with which
data land within every range)
almost 8
Why Use Frequency Distributions?
• A rate of recurrence distribution is a way to
summarize info
• The distribution condenses the natural data
into a more useful form...
• and permits a quick image interpretation
with the data
on the lookout for
Frequency Distribution:
Discrete Info
• Discrete data: likely values are countable
• Example:
A great advertiser demands 200
customers how various
days per week they
read the daily magazine
Number of
days read
Frequency
0
44
1
twenty four
2
18
3
16
4
20
5
22
6
21
7
31
Total
200
10
Frequency Distribution
Continuous Data
Model: A company of insulation randomly
chooses 20 winter season days and records the daily substantial
temperature
24, 35, 18, 21, twenty four, 37, twenty six, 46, 54.99, 30,
32, 13, doze, 38, 41, 43, 44, 27, 53, 27
(Temperature is a continuous variable since it
could be scored to any amount of precision desired)
11
Collection Data simply by Classes
Kind raw info in ascending order:
doze, 13, 18, 21, twenty-four, 24, 26, 27, twenty-seven, 30, thirty-two, 35, 37, 38, 41, 43, forty-four, 46, 53, 58
• Find selection: 58 -- 12 = 46
• Select quantity of classes: 5 (usually between 5 and 20,
k
we can use 2 n where k is number of classes and in is the range of data beliefs or work with k= 1+ 3. 3 log (n))
Smallest
• Compute class width: = Largest worth –Classes value
Number of
(46/5 then rounded off to 10)
• Determine class boundaries: twelve, 20, 31, 40, 60
• Rely observations & assign to classes
doze
Frequency Syndication Example
Info in ordered array:
doze, 13, seventeen, 21, twenty four, 24, twenty six, 27, twenty-seven, 30, thirty-two, 35, 37, 38, forty one, 43, forty-four, 46, 53, 58 Consistency Distribution
School
10 nevertheless under 20
20 but under 30
30 although under forty five
40 nevertheless under 50
50 although under 70
Total...