What is Statistics
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It is an art and science of gathering, analyzing and making inferences from data
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refers to a set of pertinent activities such as collection, presentation, analysis, and
interpretation of data
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as a process, Statistics demands answers to some questions that were formulated from an
existing situation or environment.
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it is a field of study which deals with mathematical characterization of a group or group of
items
this branch of mathematics allows us to make quantitative reasoning necessary for important
advances in the sciences such as medicine and genetics and for making important decisions in
business and public policy .
Functions of Statistics
1. It helps in collecting and presenting the data in a systematic manner.
2. It helps to understand unwisely and complex data by simplifying it.
3. It helps to classify the data.
4. It provides basis and techniques for making comparison.
5. It helps to study the relationship between different phenomena.
6. It helps to indicate the trend of behavior.
7. It helps to formulate the hypothesis and test it.
8. It helps to draw rational conclusions.
Important Concepts in Statistics:
Data may be defined as information obtained from a survey, an experiment or an investigation.
Score is the numerical evaluation of the performance of an individual on a test.
Continuous Series is a series of observations in which the various possible values of the variable may differ
by infinitesimal amounts. In the series it is possible to occur at any intermediate value within the range of
the series.
Discrete Series is a series in which the values of a variable are arranged according to magnitude or to
some ordered principles. In this series it is not possible to occur at any intermediate value within the
range. The example of such is merit, number of persons or census data.
Variable any trait or quality which has the ability to vary or has at least two points of measurement. It is
the trait that changes from one case or condition to another.
Variability: The spread of scores, usually indicated by quartile deviations, standard deviations, range etc.
Frequency may be defined as the number of occurrences of any given value or set of values. For example
8 students have scored 65. So that the score 65 has a frequency of 8.
Frequency Distribution: It is a tabulation showing the frequencies of the values of
Correlation means the interdependence between two or more random variables. It may be stated as the
tendency for corresponding observation in two or more series to vary together from the averages of their
respective series, that is, to have similar relative position.
If corresponding observations tend to have similar relative positions in their respective series, the
correlation is positive; if the corresponding values tend to be divergent in position in their respective
series, the correlation is negative; absence of any systematic tendency for the corresponding observations
to be either similar or dissimilar in their relative positions indicated zero correlation.
Coefficient: It is a statistical constant that is independent of the unit of measurement.
STATISTICS
DESCRIPTIVE
INFERENTIAL
t-test
Analysis of Variance
Analysis of Covariance
Regression analysis
Measurement of
Central Tendency
Measurement of
dispersion
VARIABLES
Qualitative
Nominal
Color- red,
yellow,
Ordinal
Fail or passed
Quantitative
Discrete
No. of students
in Stat class
Continuous
Height of
students,
p
0
