Because without representative sample, your results will not be valid.
A sample that accurately reflects the characteristics of the population as a whole
Take a simple random sample.
Well, if your sample does not represent the larger sample, you'll certainly not get a valid result ... For example, if you're studying pregnancy and your sample includes men - The whole idea of "representative' sample is fuzzy and often gives interesting errors.
A representative sample is one where the statistics of the sample are the same as the statistics for the parent population.
Many statistical statements for a population which are based on a sample are not valid if the sample is not representative.
A representative sample is a randomly selected subset of the population.
Because without representative sample, your results will not be valid.
A simple random sample.
A sample is any subset of the total population. A representative sample is one that is chosen so that its characteristics are similar to that of the population.
It is called a representative sample.
A sample that accurately reflects the characteristics of the population as a whole
That the key characteristics of the population are reflected in the sample.
Take a simple random sample.
Well, if your sample does not represent the larger sample, you'll certainly not get a valid result ... For example, if you're studying pregnancy and your sample includes men - The whole idea of "representative' sample is fuzzy and often gives interesting errors.
A representative sample is one where the statistics of the sample are the same as the statistics for the parent population.
The factors that can affect the biochemical oxygen demand (BOD) value in an experiment include the organic matter concentration in the sample, the microbial population present to break down the organic matter, the incubation time of the sample, and the temperature at which the incubation occurs. These factors can influence the rate at which oxygen is consumed in the sample, affecting the final BOD value measured.