Statistics Chapter 1

Question 1

What is the population?

Answer 1

The set of things we are interested in

Question 2

What is the sample?

Answer 2

A subset of the population

Question 3

What is a census?

Answer 3

Data collected from the whole population

Question 4

What is the sampling frame?

Answer 4

A list of the population

Question 5

What are the advantages of using a census?

Answer 5

Should give a completely accurate result as the whole population responds

Question 6

What are the disadvantages of using a census? (3)

Answer 6

Time consuming and expensive
Can’t be used if texting destroys the item
Hard to process all of the data

Question 7

What are the advantages of using a sample? (3)

Answer 7

Less time consuming and expensive
Fewer people have to respond
Less data to process

Question 8

What are the disadvantages of using a sample? (2)

Answer 8

May not be as accurate

May not represent smaller sub-groups within the population

Question 9

What is a simple random sample?

Answer 9

There is an equal chance for any unit to be picked as something like a random number generator is used

Question 10

What are the advantages of doing using simple random sample? (3)

Answer 10

Free of bias
Easy and cheap for small populations
Known and equal chance of selection

Question 11

What are the disadvantages of using a simple random sample? (2)

Answer 11

Not suitable for larger populations or sample sizes

A sampling frame is needed

Question 12

What is a systematic sample?

Answer 12

The first unit is selected randomly and then the remaining units are selected at fixed intervals

Question 13

What are the advantages of using a systematic sample? (2)

Answer 13

Simple and quick to use

Suitable for large samples and populations

Question 14

What are the disadvantages of using a systematic sample? (2)

Answer 14

A sampling frame is needed

Bias can be introduced if the sampling frame is not random

Question 15

What is stratified sampling?

Answer 15

Units are selected from the population in the correct proportion of each sub-group

Question 16

What are the advantages of using stratified sampling? (2)

Answer 16

Sample accurately reflects the population

Guarantees proportional representation of sub-groups within the population

Question 17

What are the disadvantages of using stratified sampling? (2)

Answer 17

Distinct strata are needed

Disadvantages from simple random sampling when selecting within strata

Question 18

What is opportunity sampling?

Answer 18

The first units seen are tested; i.e. the first 12 people in a queue

Question 19

What are the advantages of using opportunity sampling? (2)

Answer 19

Easy to carry out

Inexpensive

Question 20

What are the disadvantages of using opportunity sampling? (2)

Answer 20

Unlikely to provide a representative sample

Highly dependent on individual researcher

Question 21

What is a quota sample?

Answer 21

The sample reflects the characteristics of the population; certain criteria are set and a certain number of units fitting the criteria are tested

Question 22

What are the advantages of using a quota sample? (4)

Answer 22

Small sample can still be representative
No sampling frame needed
Quick, easy and inexpensive
Easy comparison of groups within a population

Question 23

What are the disadvantages of using a quota sample? (4)

Answer 23

Non-random sampling can introduce bias
Dividing the population may be inaccurate
Increasing the scope of the study increases the number of groups needed
Non-responses are not recorded

Question 24

How is stratified sampling calculated?

Answer 24

number in stratum / total frequency x sample size

Question 25

What is qualitative data?

Answer 25

Data using words

Question 26

What is quantitative data?

Answer 26

Data using numbers

Question 27

What is discrete data?

Answer 27

Data that comes in chunks, can be measured in intervals

Question 28

What is continuous data?

Answer 28

Data that can be anywhere on a scale