Large data set Flashcards
In the large data set why do some days have gaps
In the LDS, some days have gaps because the data wasnt recorded
(There are some days with no recorded data)
Explain why you have to clean the data before taking a sample
Trace data needs to be converted to numbers before calculations can be carried out
Daily mean pressure units
Hectopascal
Cloud cover units
Oktas
Daily mean visibility units
Decametres
Daily mean windspeed and direction units
Knots
Daily total rainfall units
Millimetres (mm)
How to write probability distribution for cloud cover
Random variable C can only be between 0 and 8 as cloud average is measured on a scale of 0-8 (oktas)
2 marks
Explain how the data will need to be cleaned before Ben can start to calculate statistics such as the mean and standard deviation
- Need to replace tr with a numerical value
- Value of tr is between 0 and 0.05 suggest using e.g 0.025 , 0 or value 0.05
2 marks
State two variables from the large data set for Beijing that are not suitable to be modelled by a normal distribution. Give a reason for each answer.
Daily mean wind speed/Beaufort conversion since it is qualitative
Rainfall since it is not symmetric/lots of days with 0 rainfall
