08.08.2019

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

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

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

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:

customers how various

days per week they

Number of

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...