Easy -1.3 This is a straightforward recall question testing definitions and basic sampling methodology. Part (a) requires stating a standard definition, part (b) describes a routine procedure with random number tables, and part (c) asks for a textbook example of stratification. No calculations, problem-solving, or novel application required—purely testing whether students know fundamental sampling concepts.
2. (a) Explain what is meant by a simple random sample.
(b) Explain briefly how you could use a table of random numbers to select a simple random sample of size 12 from a list of the 70 junior members of a tennis club.
(c) Give an example of a situation in which you might choose to take a stratified sample and explain why.
(a) A sample taken such that all possible samples of required size have an equal chance of being selected
B2
(b) Number members on list 01 to 70. Start at random place in table write down each 2-digit number ignoring 00, 71+ and numbers already selected until twelve numbers chosen. Identify members corresponding to selected numbers
B3
(c) e.g. survey of opinions on changing surgery hours. May wish to know views of groups such as working / not working
B2
Guidance: Example of stratified sampling
(a) A sample taken such that all possible samples of required size have an equal chance of being selected | B2 |
(b) Number members on list 01 to 70. Start at random place in table write down each 2-digit number ignoring 00, 71+ and numbers already selected until twelve numbers chosen. Identify members corresponding to selected numbers | B3 |
(c) e.g. survey of opinions on changing surgery hours. May wish to know views of groups such as working / not working | B2 | Guidance: Example of stratified sampling
2. (a) Explain what is meant by a simple random sample.\\
(b) Explain briefly how you could use a table of random numbers to select a simple random sample of size 12 from a list of the 70 junior members of a tennis club.\\
(c) Give an example of a situation in which you might choose to take a stratified sample and explain why.\\
\hfill \mbox{\textit{Edexcel S3 Q2 [7]}}