STD VIII – STATISTICS (ONLINE)

STATISTICS

Primary data

Primary data is that which is collected by the investigator himself through personal observations with a definite plan or design in mind

For example, the data collected by a teacher on the performance of students in maths

Primary data is reliable and relevant

Secondary data

Secondary data is that which has been collected previously by someone other than the investigator for some specific purpose

For example, government reports

Bar Chart

A diagram representing the frequency distribution for nominal or discrete data with comparatively few possible values

It consists of a sequence of bars or rectangles corresponding to the possible value

 Probability

Given the results of an experiment, we know how to predict the outcome of the experiment. How do we predict the outcome without actually doing the experiment? The probability or likeliness of an event occurring, without actually conducting the experiment is called theoretical probability.

Probability

Probability is defined as the numerical method of measuring uncertainty involved in a situation.

It is widely used in the study of mathematics, statistics, gambling, physical science, biological science, weather forecasting, finance etc. to draw conclusions.

Experiment:

An experiment is defined as an action or process that results in well defined outcomes.

Random experiment:

An experiment, in which we know all the results, but cannot predict them, is called a random experiment.

Outcomes:

The possible results of an experiment are called the outcomes.

Event:

A combination of outcomes is called an event.