To determine her water pressure, Denise divides up her day into three parts: morning, afternoon, and evening. She then measures
her water pressure at 2 randomly selected times during each part of the day.What type of sampling is used?a. Simple random b. Cluster c. Stratified d. Convenience e. Systematic
Stratified sampling technique is one in which the groups of data are divided into smaller groups or strata, based on shared common characteristics in these groups, and the samples randomly selected from each group in a proportional way. In this example, the sub-groups used is "times of the day" ie. morning, afternoon or evening. Other strata that can be used are; age, gender, continents etc. Stratification is done when the researcher wants to understand the relationships between the two or more groups. Stratified random sampling is also known as proportional random sampling or quota random sampling.
