STA 13 Lecture 2: stat 13: lecture 2
Document Summary
Sampling methods being in the sample (other books define this differently) Random sampling: every member of the population has the same chance of. Simple random sample (srs): simple random sample + subjects sampled. Systematic sampling: make ordered list, select a starting point then sample every independently kth member in population (1,6,11,16) k=5. Note: if we pick a random starting point then this is a random sample, but not a srs. Convenience sampling: get sample any old way that is easy. Stratified sampling: divide population into groups (strata) with similar. Ex: want to estimate average age of students in class. Then can take a separate random sample from each group. If there are large enough differences in ages between rows, then a stratified sample will give better estimate of average class age than a srs (with same total # students sampled).
