Statistics

Question 1

Define population

Answer 1

A set of items that are of interest

Question 2

Define census

Answer 2

A measure of every member of a population

Question 3

What is meant by a sampling unit?

Answer 3

A selection of the population used to estimate information about the population as a whole

Question 4

Give an advantage of a census

Answer 4

Completely accurate result

Question 5

Give 3 advantages of a sample

Answer 5

• Less time-consuming
• Fewer responses needed
• Less data to process

Question 6

Give 3 disadvantages of a census

Answer 6

• Time consuming
• Cannot be used if the sampling process would render the items unusable
• Processing a lot of data takes a long time

Question 7

Give 2 disadvantages of a sample

Answer 7

• Data might not be accurate

- Sample might not be properly representative of the population

Question 8

Describe simple random sampling

Answer 8

Selecting members will involve assigning numbers to all members of the set, and generating numbers at random to choose them

Question 9

Describe systematic sampling

Answer 9

members are chosen at regular intervals from an ordered list

Question 10

Describe stratified sampling

Answer 10

Dividing the population into groups and randomly choosing the same number from each group

Question 11

Give 3 advantages of simple random sampling

Answer 11

• Free of bias
• Easy and cheap to implement
• Every unit has an equal chance of selection

Question 12

Give 2 advantages of systematic sampling

Answer 12

• Simple and quick to use

- Suitable for large samples and populations

Question 13

Give 2 advantages of stratified sampling

Answer 13

• Sample accurately reflects the population

- Guarantees proportional representation of groups

Question 14

Give 3 disadvantages of simple random sampling

Answer 14

• Not suitable for a large population or sample size

- A sampling frame is needed

Question 15

Give 2 disadvantages of systematic sampling

Answer 15

• A sampling frame is needed

- Possible bias as units do not have an equal chance of selection

Question 16

Give 2 disadvantages of stratified sampling

Answer 16

• Population must be classified into groups which can be time-consuming
• Selection within a group has the same issues as simple random sampling

Question 17

Give the 2 types of non-random sampling

Answer 17

• Quota

- Opportunity

Question 18

What is quota sampling?

Answer 18

Where an interviewer or researcher selects a sample that reflects the characteristics of the group

Question 19

What is opportunity sampling?

Answer 19

Where the sample is taken from people available at the time and who fit the criteria needed

Question 20

Give 3 advantages of quota sampling

Answer 20

• Allows a small sample to represent the population
• No sampling frame required
• Quick and inexpensive
  Allows comparison between groups

Question 21

Give 4 disadvantages of quota sampling

Answer 21

• Potential for bias to be introduced
• Can take time to divide the population into groups after
• A more in-depth study would require an increasing number of different groups
• Some people might not be willing to take part

Question 22

Give 2 advantages of opportunity sampling

Answer 22

• Easy to carry out

- Inexpensive

Question 23

Give 3 disadvantages of opportunity sampling

Answer 23

• Unlikely to give a proportional sample
• Researcher’s ability can affect the outcome
• People might not want to be interviewed/asked

Question 24

Define quantitative data

Answer 24

Data which is numerical

Question 25

Define qualitative data

Answer 25

Data which is non-numerical

Question 26

What is discrete data?

Answer 26

Data which can only take certain values

Question 27

What’s continuous data?

Answer 27

Data which can take any value

Question 28

What are class boundaries?

Answer 28

maximum and minimum values that belong in a group

Question 29

What is the classwidth

Answer 29

the difference between the upper and lower class boundaries