Maths Stats C1

Large Data Set and sampling methods

Uk cities North to South

Leuchars

Leeming

Heathrow

Hurn

Camborne

Coastal cities

Leuchars

Camborne

Jacksonville

Perth

Overseas cities north to south

Beijing

Jacksonville

Perth

How is daily mean temp measured

degrees celsius

average of hourly temperature readings during a 24hr period

Tr daily total rainfall

Amounts less than 0.05mm. Count as 0.025mm in calculations.

Daily total sunshine accuracy

Recorded to nearest 10th of the hour

Daily mean wind direction

Bearings and as cardinal directions of which direction the wind is blowing from

Daily mean windspeed

Given in knots, averaged over 24 hrs midnight to midnight

Categorised using Beaufort Scale

Beaufort scale

0 calm (less than 1kn)

1-3 light (1 to 10 kn)

4 moderate (11 to 16 kn)

5 fresh (17 to 21 kn)

Knots to mph

1kn = 1.15mph

Daily maximum relative humidity

given as a percentage of air saturation with water vapour

about 95 percent leads to misty and foggy conditions

Daily mean visibility

measured in Dm

greatest horizontal distance at which an object can be seen in daylight

Daily mean pressure measurement

hectopascals (hPa)

systematic sampling

elements chosen at regular intervals from an ordered list

stratified sampling

population divided into mutually exclusive strata and people selected proportionally

number sampled in a stratum= (number in stratum/ population) x overall sample size