Mathematics 4 ESO – Unit 11 STATISTICS page 119 activity 3
a) Watch the video on “Stratified Sampling” and answer:
I) Using your own words define “stratified sampling”
II) We have a population with 570 students in 3rd and 4th ESO and we want a stratified sample of 60 students.
How many students of each category should be in the sample?
- b) Watch the video on “Biased Sampling” and answer:
- I) What is the difference between “biased sampling” and “unbiased sampling”?
- II) Which should you use? Why?
III) Which survey is the “biased sampling”, the first or the second? why?
- IV) Which survey is the “unbiased sampling”, the first or the second? why?