3.3 sampling

Question 1

when is a representative sample of a population selected

Answer 1

when it is impractical to measure every individual

Question 2

what determines sample size

Answer 2

the extent of the natural variation within a population

Question 3

do more variable populations require a smaller or larger sample size

Answer 3

larger

Question 4

what does a representative sample need to do

Answer 4

share the same mean and the same degreee of variation about the mean as the population as a whole

Question 5

what are the different types of sampling that can be used

Answer 5

• random
• systematic
• stratified

Question 6

what is random sampling

Answer 6

this is when members of the population have an equal chance of being selected

Question 7

what is systematic sampling

Answer 7

this is when members of a population are selected at regular intervals

Question 8

what is stratified sampling

Answer 8

the population is divided into categories that are then sampled proportionally