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Business Stats ch 8
Basic Statistics for Business and Economics ch 8
| Question | Answer |
|---|---|
| What are the reasons for sampling? | It would be time consuming. The cost of studying all the items in a population may be prohibitive. The physical impossibility of checking all the items in the population. The destructive nature of some tests. The sample results are adequate. |
| What are the sampling methods? | Simple Random Sample, Systematic Random Sample, Stratified Random Sample, and Cluster Sample. |
| Simple Random Sample | A sample selected sot that each item or person in the population has the same chance of being included. |
| Table of Random Numbers | An efficient way to select members of the sample. |
| Systematic Random Sample | A random starting point is selected, and then every kth member of the population is selected. |
| Stratified Random Sample | A population is divided into subgroups, called stra, and a sample is randomly selected from each stratum. |
| Cluster Sample | A population is divided into clusters using naturally occurring geographic of other boundaries. Then, clusters are randomly selected and a sample is collected by randomly selecting from each cluster. |
| Sampling Error | The difference between a sample statistic and its corresponding population parameter. |
| Sampling Distribution of the Sample Mean | A probability distribution of all possible means of a given sample size. |
| Central Limit Theorem | If all samples of a particular size are selected from any population, the sampling distribution of the sample mean is approximately a normal distribution. This approximation improves with larger samples. |