Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Maths A level > AS Statistics > Flashcards

AS Statistics Flashcards

1
Q

Define population

A

the whole set of items that are of interest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is a census?

A

A census observes or measure every member of a population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is a sample?

A

A selection of observations taken from a subset of the population which is used to find out information about the population as a whole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Name the advantages of a census

A

It should give a completely accurate result

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Name the disadvantages of a census

A
  1. Time consuming and expensive
  2. Hard to process large quantity of data
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Name the advantages of a sample

A
  1. Less time consuming and expensive than census
  2. Fewer people have to respond
  3. Less data to process than in a census
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Name the disadvantages of a sample

A
  1. Data may not be as accurate
  2. Sample may not be large enough to give info bout the whole population
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are sampling units?

A

Individual units of a population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is a sampling fram?

A

Sampling units named or numbered to form a list

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the 3 methods of random sampling?

A
  1. Simple random sampling
  2. Systematic sampling
  3. Stratified sampling
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is meant by simple random sampling?

A

Every sample has an equal chance of being selected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is meant by systematic sampling?

A

The required elements are chosen at regular intervals from an ordered list

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is meant by stratified sampling?

A

The population is divided into mutually exclusive strata and a random sample is taken from each

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Stratified sampling formula

A

Number in stratum/number in population X overall sample size

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Name the advantages of simple random sampling

A
  1. Free of bias
  2. Easy and cheap to implement for small populations
  3. Each sampling unit has a known and equal chance of selection
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Name the disadvantages of simple random sampling

A
  1. Not suitable when the population size or sample size is large
  2. A sampling frame is needed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Name the advantages of systematic sampling

A
  1. Simple and quick to use
  2. Suitable for large samples and large populations
18
Q

Name the disadvantages of systematic sampling

A
  1. A sampling frame is needed
  2. Can introduce bias if sampling frame is not random
19
Q

Name the advantages of stratified sampling

A
  1. Sample accurately reflects the population structure
  2. Guarantees proportional representation of groups within a population
20
Q

Name the disadvantages of stratified sampling

A
  1. Population must be clearly classified into distinct strata
21
Q

What are the two types of non-random sampling?

A

1.Quota sampling
2. Opportunity sampling

22
Q

What happens in quota sampling?

A

An interviewer or researcher selects a sample that reflects the characteristics of the whole population

23
Q

What happens in opportunity (convenience) sampling?

A

Consists of taking the sample from people who are available at the time the study is carried out and who fit the criteria you are looking for

24
Q

Name the advantages of quota sampling

A
  1. Allows a small sample to still be representative of the population
  2. No sampling frame required
  3. Quick, easy and inexpensive
  4. Allows for comparison between different groups within a population
25
Q

Name the disadvantages of quota sampling

A
  1. Non-random sampling can introduce bias
  2. Population must be divided into groups which can be inaccurate
  3. Non responses are not recorded
26
Q

Name the advantages of opportunity sampling

A
  1. Easy to carry out
  2. Inexpensive
27
Q

Name the disadvantages of opportunity sampling

A
  1. Unlikely to provide a representative sample
  2. Highly dependent on individual researcher
28
Q

What are quantitative variables/data?

A

Variables/data associated with numerical observations

29
Q

What are qualitative variables/data?

A

Variables/data associated with non-numerical observations

30
Q

What is meant by a continuous variable?

A

A variable that can take any value in a given range

31
Q

What is meant by a discrete variable?

A

A variable that can take only specific values in a given range

32
Q

What is a knot (kn)?

A

A nautical mile per hour

33
Q

What is the Beaufort scale used for?

A

The data for mean windspeed

34
Q

How is data for mean windspeed shown?

A

Using the Beaufort scale

35
Q

What is measured in knots?

A

Daily maximum gust

36
Q

What is measured in oktas?

A

Daily mean cloud cover

37
Q

What is measured in decametres?

A

Daily mean visibility

38
Q

What is measured in hectopascals?

A

Daily mean pressure

39
Q

What is meant by “cleaning the data”

A

the process of removing anomalies

40
Q

What is meant by bivariate data?

A

Data which has pairs of values for two variables

Maths A level (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions