statistics

MATHS ACTIVITY

DataThe word data means information or set of given facts in numerical figures

Statistics It is the science which deals with the collection, presentation, analysis and interpretation of numerical

Types of Data Primary Data : The data collected by the investigator himself with a definite plan in mind are known as primary data

Secondary Data : The data collected by someone, other than the investigator, are known as secondary data

Ungrouped DataThe data obtained in original form are called ungrouped data

Grouped Data We may condense data into classes or groups. Such a presentation is known as grouped data

Array An arrangement of raw numerical data in ascending or descending order of magnitude, is called an array

Presentation of Data Putting the data, in the form of tables, in condensed form, is known as the presentation of data

Frequency of an Observation The number of times an observation occurs is called its frequency

Types of Frequency DistributionExclusive Form

A frequency distribution in which each upper limit of class is excluded and lower limit is included

Inclusive Form A frequency distribution in which each upper limit as well as lower limit is included

Some Definitions Variate or Variable

Any character which is capable of taking several different values is called a variable

Class Interval Each group into the raw data is condensed, is called class interval

Class Size The difference between the true upper limit and the true lower limit of a class

Class Mark of a Class =

Range

Upper limit + lower limit

2

The difference between the maximum value and the minimum value of the variate

Cumulative Frequency The cumulative frequency corresponding to a class is the sum of all frequencies up to and including that class

Bar Graph

Histogram

Frequency Polygon

Central Tendency3 M’s

Mean Median Mode

Arithmetic Mean sum of observations Mean = number of observations

Three methods to find mean • Direct method • Assumed method• Step Deviation method

MedianIf n is odd, Median = n+1 2If n is even ,Median =mean of (n)th and (n+1) 2 2

Mode Empirical formula Mode = 3(Median) – 2(Mean)

Thank you Presented by

Prithvi, Rahul, Vignesh, Dinesh and Naveen