what are the difference between this two??can you explain the random selection? what is projected error??what kind of error is counted projected error?
Random selection is where each member of the population has an equal chance of selection and is carried out by numbering each item of the population then using random number tables to choose which items to examine. Haphazard means that a person picks items, presumably trying to emulate randomness. However, that person’s choice could easily be biased ie not truly random.
Projected error = Error found in sample x Population value/Sample value