Respresentative sample

Respresentative sample?

explain the meaning of this term, details of this sample

Other Answers:

If you are learning statistics, sampling is a way of predicting the behaviour of a whole population from a sample. A representative sample should have the same proportions of different classes as the total population. In this way, the sample "represents" the whole population.

When trying to gather information, it is generally easier to ask / measure a sample of your target audience than to ask/ measure every one. However for this to work, the sample should be representative of the group as a whole.

E.g at election times, the media are all desperately trying to predict how the election is going to go, obviously they don't ask everyone who can vote, so they have to ask a sample of the population as a whole. For their polls to have any meaning, the sample of people they do ask, must try to represent the population as a whole. This means asking, men, women, rich, poor, employed, unemployed, black, white, English, Irish, Scottish, Welsh, etc. And all combination thereof. I'm sure you can see why representative samples are seldom truly representative.

As a rule of thumb, the smaller the sample in comparison to the actual size of people/ opinions/ things you are trying to sample, the less it truly represents that which you are sampling.

As for 'details of this sample' this would be specific to each example.

E.g if you are trying to determine the average of how many people are usually in a car, you could stand at a junction and count people in cars as they go by. However if you stand near a school, the numbers will be significantly different depending on whether your junction is on the way to school or the way back (mum has dropped off or picked up little Johnny)

If you are trying to find the average weight of an apple, you could weigh 6 of them and take the average, weighing 12 would be more representative, weighing 50,000 would be really representative (though costly to carry out). Your sample would only be valid for the type(s) of apple you weigh. I'm sure the average weight for a bramley is different to that of a golden delicious.

A REPS SAMPLE - WHAT NEEDS EXPLAINING! A REP SELLING SWEETS WOULD GIVE YOU A SAMPLE OF SWEETS! DOH