# Stats - Large Data Sets

> Source: https://ollybritton.com/notes/a-level/maths/topics/stats/large-data-sets/ · Updated: 2020-09-29 · Tags: stats, year-1, school

##### What data does Pearson's large data set contain??
Information from weather stations.

##### When did the weather stations in Pearson's large data set record data??
* May-Oct 1987
* May-Oct 2015

##### Why was Oct 1987 of interest??
Because of The Great Storm.

##### What are the units for mean temperature??
^{\circ} C

##### What are the units for total rainfall??
$mm$

##### What does tr/trace mean in relation to total rainfall??
Less than 0.05mm rain.

##### What are the units for total sunshine??
Hours.

##### To what accuracy are the units for total sunshine??
The nearest tenth of an hour.

##### What are the __two__ different units for daily mean windspeed??
$\text{knots}/\text{kn}$ or the beaufort scale.

##### How many $mph$ in $1kn$??
$$
1kn \to 1.15mph
$$

##### What is the Beaufort scale??
A way of describing the wind speed.

##### What are the units for maximum gust??
$\text{knots}/\text{kn}$

##### What is the "maximum gust"??
The maximum instantaneous wind speed.

##### What are the units for humidity??
A percentage of water-air saturation.

##### What does 100% represent in terms of humidity??
The maximum amount of water saturation in the air.

##### What are the units for mean cloud cover??
Oktas.

##### What is an Okta??
Describes the amount of cloud coverage in the sky.

##### One Okta represents what fraction of the sky obscured by cloud??
$$
\frac{1}{8}
$$

##### What are the units for mean visibility??
Metres.

##### How is mean visibility measured??
The amount that can be seen into the horizon during daylight.

##### What are the units for air pressure??
Hectopascals ($hPa$).

##### What are the four cardinal directions??
N, E, S, W.

##### What are the two ways wind direction is measured??
* A cardinal direction
* A bearing

##### What two data points about wind direction are recorded (not units)??
* Max gust direction
* Average wind direction

##### Where is Leuchards??
In Scotland.

##### Where is Leeming??
In the Midlands.

##### Where is Heathrow??
In London.

##### Where is Hurn??
Near Bournemouth.

##### Where is Camborne??
In Cornwall.

##### In what country is Bejing??
China.

##### In what country is Jacksonville??
USA.

##### In what country is Perth??
Australia.

##### In what hemisphere is Bejing??
North.

##### In what hemisphere is Jacksonville??
North.

##### In what hemisphere is Perth??
Australia.

### 2022-05-04
##### How many pascals is one hectopascal??
$$
100
$$

##### What shouldn't you say as a reason why a simple random sample might not give the desired number of samples??
Don't say it's because there might be repeats.

##### If a small sample of large data set seems to agree with a hypothesis, should you jump to the conclusion that it's good evidence for that hypothesis being true??
No, the sample size might be too small.

### 2022-05-08
##### What is mnemonic to remember the weather stations in the large data set??
Look! LLarge HHadron Collider, Bussin' Job Piranha!

##### Is cloud cover (in Oktas) a discrete or a continuous variable??
Discrete.

##### Using the mnemonic, can you list all weather stations in the large data set??
* Leuchars
* Leeming
* Heathrow
* Hurn
* Camborne
* Beijing
* Jacksonville
* Perth

### 2022-05-16
##### What is a bad reason for stating you can't model a variable in the large data set??
Saying that it is discrete.

##### Why can't you model the wind speed (using the Beaufort scale) with a normal distribution for the large data set??
Because it is non-numeric (not because it is discrete!!)

##### Why can't you model the daily rainfall with a normal distribution for the large data set??
Because the distribution is not bell shaped.

##### What's another reason apart from values being non-numeric that a variable can't be modelled using a normal distribution??
The actual distribution that describes it might not be symmetric.

### 2022-05-17
##### What fairly obvious thing do you get less of the sunnier it is??
Rainfall!

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