EC255 Lecture Notes - Lecture 7: Central Limit Theorem, Standard Deviation, Simple Random Sample
Document Summary
Eliminate the possibility that by chance a random sample may not be representative of the population. Sampling can broaden the scope of the data set. Research process is sometimes destructive sample can save product. Using data obtained through sampling to estimate the value of or test a hypothesis about a parameter (inductive logic) Random sampling: every unit of the population has the same probability of being included in the sample. Chance mechanism is used in the selection process. Nonrandom sampling: every unit of the population doesn"t have the same probability of being included in the sample. Not appropriate data collection methods for most statistical methods. Proportionate: % of the sample taken from each stratum is proportionate to the % that each stratum is within the whole population. Disproportionate: % of the sample taken from each stratum is not proportionate to the % that each stratum is within the whole population.
