Statistics mis(1)

What is meant by Hypothesis ?
Hypothesis refers to a statement asserting that a
sample is different from the population on µthe variable
x≠

of interest.
x=µ
What is meant by Null hypothesis ?
Null hypothesis refers to a statement of “no
difference” between a sample and a population.
x≠µ

©.S. B. Bhattacharjee Ch_1_1

What is meant by proportion?
The proportion refers to the number of cases in one
category of a variable divided by number of cases in all
categories of the variable.

What is meant by ratio?

It is the number of cases in one category divided by the
number of cases in some other category.
Female=10
Male= 20


What is meant by mid- point ?

This is the point exactly halfway between the upper
and lower limits of a class interval.

What is meant by bivariate table?
It is a table that displays the joint frequency
distribution of two variables.
What is meant multiple table?
It is a table that displays the joint frequency
distribution of more than two variables.


What is meant by rate?
It is the number of actual occurrences of some
phenomenon or trait divided by the number of possible
occurrences per some unit of time.
Number of deaths
Crude death rate = × 1000 per year
Total populations
Number of deaths = 10
Total population = 1000
10
Crude death rate = × 1000
1000
= 10


What is meant by data ?
Data refer to information expressed as numbers.

What is percentage?
It is the number of cases in a category of a variable
divided by the number of cases in all categories of the
variables, multiplied by 100.
What is bar chart?
A bar chart is a graphic display device for nominal and
ordinal variables.


What is frequency distribution ?
It is a table that displays the number of cases in each
category of a variable .

What is frequency polygon?
It is a graphic display device for interval–ratio
variables.

What is histogram?
It is a graphic display device for inter–ratio variables.


What are characteristics of the
three levels of measurement?


Table 1.3
Basic Characteristics of the three levels of measurement

Measurement Mathematical
Levels Examples
procedures operations permitted
Nominal Sex, race Classification into Counting number
religion, categories of cases in each
marital status category of the
variable;
comparing sizes of
categories

Social class Classification into All above plus
Ordinal
(SES), attitude categories plus judgments of
and opinion ranking of “greater than” and
scales categories with “less than”
respect to each
other
Continued…….

Table 1.3
Levels Examples

Interval- Age, number of All above plus All above plus all other
ratio children, income distances mathematical
between scores operations (addition,
can be subtraction,
described in multiplication, division,
terms of equal square roots, etc.)
units


What is meant by a variable ?
A variable is any trait that can change values from case
to case.

Example:

Person Age
A 20
B 25
C 30
D 31


What are the levels of measurement ?


Table 1.3
Levels Examples
Normal Sex, race Classification into Counting number of
religion, categories cases in each category
of the variable;
marital status
comparing sizes of
categories

Ordinal Social class Classification into All above plus
(SES), attitude categories plus judgments of “greater
and opinion ranking of than” and “less than”
scales categories with
respect to each
other

©.S. B. Bhattacharjee Continued……. Ch_1_12

Table 1.3
Levels Examples

Interval- Age, number of All above plus All above plus all other
ratio children, income distances mathematical
between scores operations (addition,
can be subtraction,
described in multiplication, division,
terms of equal square roots, etc.)
units


What is meant by mean?
The mean is an average that is computed by
adding up the scores and then diving the same
by the number of scores.
Example:
10, 20, 30


What is meant by mode?
The mode of any distribution is the value that
occurs most frequently.
Example:
58, 82, 82, 90, 98
Here the mode is 82 since it occurs twice and
others scores occur only once.


What is meant by median?
The median is the exact center of a distribution
scores. It is the point in a distribution of scores
above and below which exactly half of the cases
fall.
Example:
10, 15, 20, 25, 30


What is meant by guidelines that one has to
keep in mind in choosing a measure of central
tendency?
The mode may be used when:

Variables are measured at the nominal level.
You want a quick and easy measure for ordinal
and interval-ratio variables.
You want to report the most common score.


tendency?
The median may be used when:

Variables are measured at the ordinal level.
Variables measured at the interval-ratio level
have badly skewed distributions.
You want to report the central score. The
median always lies at the exact center of a
distribution.

©.S. B. Bhattacharjee Continued…….. Ch_1_18

tendency?
The mean may be used when:

Variables are measured at the interval-ratio
level (except for badly skewed distributions).
You want to report the typical score. The mean
is “ the fulcrum that exactly balances all of the
scores.”
You anticipate additional statistical analysis.


What are the data from counseling
center survey?


Table 2.4
Marital Satisfaction
Student Sex Age
Status With Services

A Male Single 4 18
B Male Married 2 19
C Female Single 4 18
D Female Single 2 19
E Male Married 1 20
F Male Single 3 20
G Female Married 4 18
Continued….

Table 2.4
Student Sex Age

H Female Single 3 21

I Male Single 3 19

J Female Divorced 3 23

K Female Single 3 24

L Male Married 3 18

M Female Single 1 22

N Female Married 3 26

Continued….

Table 2.4
Student Sex Age

O Male Single 3 18
P Male Married 4 19
Q Female Married 2 19
R Male Divorced 1 19
S Female Divorced 3 21
T Female Single 2 20


Application 2.4
The following list shows the ages of 50 prisoners enrolled in a
work-release program. Is this groups young or old? A frequency
distribution will provide an accurate picture of the overall age
structure. 18 57 27 19 60
20 32 62 26 20
25 35 75 25 21
30 45 67 41 30
37 47 65 42 25
18 51 22 52 30
22 18 27 53 38
27 23 32 35 42
32 37 32 40 45
55 42 45 50 47

©.S. B. Bhattacharjee Continued……. Ch_1_24

Application 2.4

Continued…….

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