Brainscape's Knowledge GenomeTM

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


See full index

AS Pure Maths > Statistics 1 > Flashcards

Statistics 1 Flashcards

1
Q

Define population

A

Whole set of items of interest

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

Define census

A

Observation/measure of every member of the population

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

Define sample

A

Selection of observation from a subset of population in order to discover information about the population in its entirety

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

Advantage of a census?

A

-Completely accurate result obtained

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

Disadvantages of a census?

A

-Time-consuming and expensive
-Not used when testing involves the destruction of the item
-Hard to process large quantity of data

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Advantages of a sample?

A

-Less-time consuming and expensive
-Fewer people required to respond
-Less data to be processed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Disadvantages of a sample

A

-Data could be inaccurate
-Sample could not be large enough to inform of whole population by small sub-groups used

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Correlation between a sample size and the validity of conclusions of the processed data.

A

Larger size of sample usually increases the validity of the conclusions of the processed data.

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

What does the size of a sample depend on.

A

-Accuracy required
-Resources available

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

Why is larger sample typically more accurate.

A

Larger proportion of data examined, more likely to be representative of population.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

If population is very varied.

A

Size of sample required would be larger than that of a uniform population.

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

Different samples can…

A

Lead to different conclusions due to the natural variation of a population.

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

Define sampling units.

A

The individual units of a population available for sampling.

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

Define sampling frame.

A

Where sampling units are individually named/numbered to form a list.

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

Define random sampling.

A

Where every member of the population has an equal chance of being selected for sampling.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Thus, the sample performed under the methods of random sampling should be…

A

More representative of the population.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Benefit of random sampling as a whole.

A

It helps to eradicate the bias from sampling.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the 3 types of random sampling.

A

-Simple random
-Systematic
-Stratified

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Discuss the method undergone of simple random sampling.

A

-Requirement of sampling frame.
-Utilisation of random number function of calculator or “lottery sampling”.
-Lottery sampling is where the members of the sampling frame are placed in a hat/other appropriate item, and then the required number of “tickets” are drawn from this object.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the advantages of simple random sampling.

A

-No bias
-Easy and cheap for small populations and small samples
-Each sampling unit has known and equal chance of selection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Disadvantages of simple random sampling.

A

-Not suitable with large population/sample size
-Requirement of a sampling frame.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Discuss the method undergone in systematic sampling.

A

-Required elements chosen at regular intervals from sampling frame.
-1st person chosen should be of randomised, then from then on the succeeding units are chosen at regular intervals from the sampling frame.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Describe the advantages of systematic sampling.

A

-Simple and quick
-Suitable for large populations and sample sizes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Describe the disadvantages of systematic sampling.

A

-Requirement of sampling frame
-If the 1st person chosen is not randomised, bias can be introduced into the sampling.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Discuss the method undergone to perform stratified sampling.

A

-Population divided into mutually exclusive strata and random sampling occurs from each strata.
-The PROPORTION of each strata should be equal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the equation that decides what the number of strata will be to ensure its proportion of the overall population is equal to the rest.

A

No. of sample in the strata+ no of strata/no. of overall population x overall sampling size

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are the advantages of stratified sampling.

A

-Sample accurately reflects the population structure
-Guarantees proportional representation of groups within the population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are the disadvantages of stratified sampling.

A

-Population required to be classified into distinct strata.
-Selection process within each strata is not suitable for large population/ sample sizes
-Requirement of sampling frame.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are the 2 types of non-random sampling.

A

-Quota sampling
-Opportunity/Convenience sampling.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Describe quota sampling.

A

-Interviewer/researcher selects a sample to try to reflect the characteristics of a population.
-Population divided into groups according to the given characteristic, with the size of each group determining the proportion of the sample that will have that specific characteristic.
-Interviewer meets people, assesses group, and subsequently allocates them into the appropriate quota
-This continues until all the quota are filled.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What occurs if a person refuses to be interviewed/person fits into quota already filled?

A

Simply ignored and researcher/interviewer moves onto next person.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What are the advantages of quota sampling.

A

-Allows a small sample to still be representative of the population
-Not requiring a sampling frame.
-Quick, easy, inexpensive.
-Allows for easy comparison between the different groups of a population.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What are the disadvantages of quota sampling.

A

-Methods of non-random sampling can introduce bias
-Population must be divided into groups, which can be costly or inaccurate.
-Increase scope of the study increases the number of groups, hence increasing the time and expense.
-Non-responses are recorded as such.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is the method of opportunity sampling.

A

-Taking the sample from people available at the time of sampling who fit the criteria that is being researched.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Advantages of opportunity sampling.

A

-Easy to carry out
-Inexpensive.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Disadvantages of opportunity sampling.

A

-Unlikely that the sampling is representative of the population
-Is highly dependent on the individual researcher

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is qualitative data/variables.

A

Variables/data associated with numerical observations.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Quantitative?

A

Variables/data associated with non-numerical observations.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is a continuous variable.

A

A variable that can take any value of a given range.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is a discrete variable.

A

-Variable that can only take specific values in a given range.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What is sometimes helpful to be done for large data?

A

To display it in frequency tables/as grouped data.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Discuss the features of a grouped frequency table.

A

-Specific data values not shown
-Groups called classes
-Class boundaries are the maximum and minimum values that belong to each class
-Midpoint= Average of class boundaries.
-Class width= Upper class boundary- lower class boundary (difference of both)

43
Q

What are the 5 UK weather stations.

A

-Camborne
-Hurn
-Heathrow
-Leeming
-Leuchars

44
Q

What are the coastal weather stations.

A

-Camborne
-Hurn
-Leuchars

45
Q

What are the inland weather stations.

A

-Heathrow
-Leeming

46
Q

What is the westernmost UK weather station.

A

Camborne.

47
Q

What UK weather station is the closest to the Isle of Wight.

A

Hurn

48
Q

What is the northernmost weather station.

A

Leuchars

49
Q

What is the 2nd most northernmost weather station.

A

Leeming.

50
Q

What is the only non-English (Scottish) weather station.

A

Leuchars.

51
Q

What are the 2 international weather stations.

A

-Jacksonville, USA
-Beijing, China
-Perth, Australia.

52
Q

What are the coastal international weather stations.

A

-Jacksonville
-Perth

53
Q

What is the inland international weather station.

A

-Beijing

54
Q

What is the southernmost weather station.

A

Perth

55
Q

What is the westernmost weather station.

A

Perth

56
Q

What is the only weather station of the Southern Hemisphere.

A

Perth

57
Q

What is the daily mean temperature.

A

Average of hourly readings of temperature in a 24-hour period.

58
Q

Where is the temperature recorded.

A

1.25m from ground level, by thermometers with a lowered screen above short grass.

59
Q

What is the units of daily mean temperature.

A

Degrees celscius

60
Q

When is the daily mean temperature recorded.

A

0900 to 0900 GMT.

61
Q

What is daily total rainfall measured in.

A

mm

62
Q

What, as well as rain are measured? How are they made recordable?

A

-Solid precipitation like hail/snow
-They are melted before being measured.

63
Q

What are amounts less than 0.05mm recorded as.

A

Tr (trace)

64
Q

When is daily total rainfall measured.

A

0900 to 0900 GMT.

65
Q

What is daily total sunshine.

A

-Amount of solar radiation that exceeds a threshold.

66
Q

What are they recorded in.

A

Neatest tenth of an hour.

67
Q

What is daily mean wind direction recorded in.

A

Knots (nautical mph)
1 knot=1.15 mph

68
Q

When is daily mean wind direction recorded.

A

Average of data recorded between 0000 to 0000 GMT

69
Q

How are wind directions (meaned) recorded.

A

-As bearings/cardinal (compass) direction, rounded to the nearest 10 degrees.

70
Q

How is the daily mean windspeed recorded according to.

A

The Beaufort scale.

71
Q

How is daily mean windspeed measured.

A

A visiometer.

72
Q

Where is daily mean windspeed recorded from.

A

Averaged data recorded from 10m above ground level.

73
Q

What is the scale and term for windspeed less than 1km.

A

Scale=0
Term=Calm

74
Q

What is the scale and term for windspeed of 1-10km.

A

Scale=1-3
Term= Light

75
Q

What is the scale and term for windspeed of 11-16km.

A

Scale= 4
Term= Moderate

76
Q

What is the scale and term for windspeeds of 17-21km.

A

Scale=5
Term=Fresh

77
Q

What are the ONLY measurements conducted by international weather stations.

A

-Daily mean temperature
-Daily total rainfall
-Daily mean windspeed

78
Q

What is daily maximum gust.

A

-Highest instantaneous windspeed recorded.
-Direction from which the maximum gust blows is also recorded.

79
Q

What is the units of daily maximum gust.

A

Km

80
Q

What is daily maximum relative humidity.

A

How close air is to becoming saturated by water vapour

-Official term= percentage of air saturation that is water vapour.

81
Q

What are causative of relative maximum humidities of more than 95%?

A

Foggy/misty conditions.

82
Q

How is daily mean cloud cover measured.

A

Oktas= eighths of sky covered by cloud.

83
Q

What is the daily mean visibility.

A

Greatest horizontal distance at which an object can be seen in daylight.

84
Q

What would be the nightly mean visibility hence.

A

Greatest horizontal distance at which an object could be seen in the GENERAL ILLUMINATION OF DAYLIGHT.

85
Q

What is daily mean visibility measured in.

A

Decametres

86
Q

How is daily mean pressure recorded.

A

Hectopascals.

87
Q

How is daily mean pressure recorded.

A

Pressure at station level of the sea.

88
Q

When was data recorded from the specific weather stations to create the large data set.

A

-May-October 1987
-May-October 2015

89
Q

How are missing values indicated.

A

N/a (not available)

90
Q

Typical tendency of coastal locations.

A

Increased wind.

91
Q

Typical tendency of northern locations.

A

Decreased temperature

92
Q

Wettest city of 2015?

A

Jacksonville

93
Q

Windiest month of 2015?

A

May

94
Q

Wettest UK city of 2015?

A

Camborne

95
Q

Warmest UK location on average of 2015?

A

Heathrow

96
Q

Wettest month of 2015?

A

August

97
Q

Importance of 1987.

A

-Great Storm occurred
-On midnight of 15-16 October.

98
Q

Importance of 2015.

A

-Heathrow Airport affected by heavy rains of 26 August

99
Q

Temperature of international weather stations in ascending order of 2015.

A

-Jacksonville (coldest)
-Beijing
-Perth

100
Q

2015 importance for UK?

A

30 June, temperatures above 30 degrees celsius recorded.

101
Q

Importance for knowledge on place of measurements.

A

-Consistency
-Comparison

102
Q

Type of data collection that the Large Data Set is.

A

Secondary

103
Q

Importance of Heathrow geographically in terms of windspeed.

A

Windspeeds tendency to be high due to is affect of arrivals and departures in its airport.

AS Pure Maths (1 decks)

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