Suppose a researcher is looking at a population of 180,000 people and wants to use a sample of 50,000 stratified by using age range. The researcher would use the formula: The same method is used ...

Mary Hall is a editor for Investopedia's Advisor Insights, in addition to being the editor of several books and doctoral papers. Mary received her bachelor's in English from Kent State University ...

Consider the example in the section "Stratified Sampling". The study population is a junior high school with a total of 4,000 students in grades 7, 8, and 9. Researchers want to know how much these ...

Producers of infant formula employ comprehensive food safety systems ... Spacing out samples over time in a stratified sampling pattern is better at catching risky pathogens like Cronobacter than ...