A statistical population is the collection of every member of a group possessing the same basic and defined
characteristic, but varying in amount or quality from one member to another.
IQ’s of all children in a school.
· Infinite population:
Barometric pressure:
(There are an indefinitely large number of points on the surface of the earth).
A flight of migrating ducks in Canada
(Many finite pops are so large that they can be treated as effectively infinite). The examples that we have just
considered are those of existent populations.
A hypothetical population can be defined as the aggregate of all the conceivable ways in which a specified event can
happen.
We also need to differentiate between the sampled population and the target population. Sampled population is that from which a sample is chosen whereas the population about which information is sought is called the target population thus our population will consist of the total no. of students in all the colleges in the Punjab.
Suppose on account of shortage of resources or of time, we are able to conduct such a survey on only 5
colleges scattered throughout the province. In this case, the students of all the colleges will constitute the target pop whereas the students of those 5 colleges from which the sample of students will be selected will constitute the sampled population. The above discussion regarding the population, you must have realized how important it is to have a very well-defined population.
The next question is: How will we draw a sample from our population?
The answer is that: In order to draw a random sample from a finite population, the first thing that we need is the complete list of all the elements in our population.
This list is technically called the FRAME.
characteristic, but varying in amount or quality from one member to another.
EXAMPLES
· Finite population:IQ’s of all children in a school.
· Infinite population:
Barometric pressure:
(There are an indefinitely large number of points on the surface of the earth).
A flight of migrating ducks in Canada
(Many finite pops are so large that they can be treated as effectively infinite). The examples that we have just
considered are those of existent populations.
A hypothetical population can be defined as the aggregate of all the conceivable ways in which a specified event can
happen.
For Example:
- All the possible outcomes from the throw of a die – however long we throw the die and record the results,we could always continue to do so far a still longer period in a theoretical concept – one which has no existence in reality.
- The No. of ways in which a football team of 11 players can be selected from the 16 possible members named by the Club Manager.
We also need to differentiate between the sampled population and the target population. Sampled population is that from which a sample is chosen whereas the population about which information is sought is called the target population thus our population will consist of the total no. of students in all the colleges in the Punjab.
Suppose on account of shortage of resources or of time, we are able to conduct such a survey on only 5
colleges scattered throughout the province. In this case, the students of all the colleges will constitute the target pop whereas the students of those 5 colleges from which the sample of students will be selected will constitute the sampled population. The above discussion regarding the population, you must have realized how important it is to have a very well-defined population.
The next question is: How will we draw a sample from our population?
The answer is that: In order to draw a random sample from a finite population, the first thing that we need is the complete list of all the elements in our population.
This list is technically called the FRAME.
No comments:
Post a Comment