Respuesta :

The sampling technique used  when A  scientist chooses twenty people at random from each class is stratified sampling.

What is stratified sampling?

Stratified sampling can be described as the type of  sampling method whereby the  total population is been divided into smaller groups or strata.

This usually done  to complete the sampling process, hence The sampling technique used  when A  scientist chooses twenty people at random from each class is stratified sampling.

Read more on the stratified sampling here:

https://brainly.com/question/1954758

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