Brainscape's Knowledge GenomeTM

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


See full index

A LEVEL - Maths > Statistics > Flashcards

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

Define a census.

A

A study that measures or observed every member of a population.

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

Define a sample.

A

A selection of observations taken from a subset of the whole 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

Define sampling units.

A

Individual units of a population.

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

Define sampling frame.

A

A ordered list of sampling units (e.g. a list of people).

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

What are the two general types of sampling?

A
  • Random sampling

* Non-random sampling

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

What are the three types of random sampling?

A
  • Simple random sampling
  • Systematic sampling
  • Stratified sampling
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is simple random sampling?

A
  • Sampling frame is made

* A random selection of sampling units is made

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

What is systematic sampling?

A
  • Sampling frame is made

* The required number of elements are taken at regular intervals

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

What is stratified sampling?

A
  • Population is divided into mutually exclusive strata
  • Random sample is taken within each
  • The number of samples taken in each stratum should be proportional to its representation in the general population
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the two types of non-random sampling?

A
  • Quota sampling

* Opportunity sampling

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

What is quota sampling?

A
  • Population is divided into groups according to a given characteristic
  • The size of each group determines the proportion of the sample that should have that characteristic
  • As you meet people, they are assessed and allocated into the appropriate quota
  • This is done until all the quotas have been filled
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is opportunity sampling?

A
  • Taking the sample from the first people who are available at the time the study and who fit the criteria
  • This is done until enough samples are taken
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the difference between stratified sampling and quota sampling?

A
  • Stratified sampling -> Random -> People within each stratum are selected at random
  • Quota sampling -> Not random -> You do not know your sampling frame and people are not chosen at random
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is another name for opportunity sampling?

A

Convenience sampling

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

Define continuous data.

A

Data that can taken any value within a given range.

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

Define discrete data.

A

Data that can only take on certain specific values within a range.

18
Q

What dates does the large data set contain data from?

A
  • May to October 1987

* May to October 2015

19
Q

What weather stations are used in the large data set?

A
  • Leuchars
  • Leeming
  • Heathrow
  • Hurn
  • Cambourne
  • Jacksonville
  • Beijing
  • Perth
20
Q

Name the UK weather stations in the large data, starting from the north and going clockwise.

A
  • Leuchars
  • Leeming
  • Heathrow
  • Hurn
  • Cambourne
21
Q

Name the only weather station in the large data set that is in the Southern hemisphere.

A

Perth

22
Q

In the large data set, what is the daily mean temperature and what are the units?

A
  • The average of the hourly temperatures during a 24-hour period
  • °C
23
Q

In the large data set, what is the daily total rainfall and what are the units?

A
  • The total precipitation including solid precipitation, like snow and hail
  • Amounts less than 0.05mm are recorded as trace.
  • mm
24
Q

In the large data set, what is the daily total sunshine and what are the units?

A
  • The total sunshine time
  • Recorded to the nearest tenth of an hour
  • hrs
25
Q

In the large data set, what is the daily mean wind direction and windspeed and what are the units?

A
  • The average wind speed over 24 hours
  • Knots (kn)
  • Direction is given as a bearing and compass directions
  • Windspeed is also categories affording to the Beaufort scale p
26
Q

On what scale is wind speed measured?

A

Beaufort scale

27
Q

In the large data set, what is the daily maximum gust and what are the units?

A
  • The highest instantaneous windspeed recorded
  • The direction it is blowing from is also recorded
  • Knots (kn)
28
Q

In the large data set, what is the daily maximum relative humidity and what are the units?

A
  • The air saturation with water vapour

* Given as a percentage

29
Q

In the large data set, what is the daily mean cloud cover and what are the units?

A
  • The mean cover of the sky with clouds

* Oktas (or eighths of the sky covered)

30
Q

In the large data set, what is the daily mean visibility and what are the units?

A
  • The greatest horizontal distance at which an object can be seen in daylight
  • Decametres (Dm)
31
Q

In the large data set, what is the daily mean pressure and what are the units?

A
  • The average air pressure for that day

* Hectopascals (hPa)

32
Q

When comparing data sets, what can you comment on?

A
  • Measure of location
  • Measure of spread

Use the mean and standard deviation OR median and IQR. But not any other combination.

33
Q

When a data set contains extreme values and it needs to be compared, is it more appropriate to use the mean and standard deviation or median and IQR?

A

Median and IQR

34
Q

What are some other names for the independent and dependent variables?

A
  • Independent -> Explanatory variable

* Dependent -> Response variable

35
Q

What is bivariate data?

A

Data which has pairs of values for two variables.

36
Q

What is a sample space?

A

The set of all outcomes in an experiment or the set of all values that a random variable can take on.

37
Q

What is the term for when all of the probabilities in a sample space for a variable are the same?

A

Discrete uniform distribution

38
Q

In binomial distributions, what is n sometimes called?

A

The index

39
Q

In binomial distributions, what is p sometimes called?

A

The parameter

40
Q

What is the way of writing binomial distributions, and what does each letter stand for?

A

X~B(n,p)
P(X=r)

Where:
• X = Variable
• B shows it is binomial
• n = Number of trials
• p = Probability of success
• r = Number of successful trials
41
Q

What is a cumulative probability function?

A

One that tells you the sum of all the individual probabilities up to and including the given value of x in the calculation.

A LEVEL - Maths (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions