STATS AND MECH Flashcards
Daily mean temperature
Average temp readings for 24 hours
DEGREES
Daily total rainfall
in mm
Trace is <0.05
0 when doing mean
Daily total sunshine
Nearest tenth of an hour
It’s the amount bright sunshine
Daily maximum relative humidity
% of air with water vapour
over 95 is fog
Daily mean wind speed
In knots
In Beaufort scale
1 knot in km
1.8
Beaufort scale range
0 - calm
6 - strong breeze
12 - hurricane
Daily maximum gust
Maximum wind speed in a day
In knots
Daily mean wind direction
From north a bearing not padded with 0s
Rounded nearest 10
Cloud cover
In oktas, fraction of sky covered by cloud
0-8
Visibility
DECAMETERS (10cm)
Greatest distance an object can be seen in daylight
Mean pressure
Mean pressure at sea level In hPa (100pa)
Typical pressure range
900-1100hPa
Frequency, cw, density equation
freq = fd* cw
How to prove statically independent
P(A) * P(B) == P(A n B)
Answer to ‘why include this reading/stat’
It is a piece of data and we should consider all the data
Answer to ‘why exclude this reading/stat’
It is an extreme value and could unduly influence the analysis
How to answer give an interpretation of the correlation between X and Y
as X (in/decreases), Y (in/decreases)
How to answer ‘give interpretation of regression line’
a X amount increase in X gives rise to a Y increase in Y
How to answer comment on suitability of sampling method
Anything valid such as ‘could use from more locations/from more months’
How to answer suggest how would better use the large data set
Use more locations and more of the months
How to answer comment on validity of the model to obtain answer
RELATE the sampling type to the question, eg is the sample random?
How to explain restriction in polynomial function (eg for some range of values of X)
Substitute the min and max range
Show some sort of relationship between the answers to the subbed in
Link it, explain ‘eg it must be positive’
How to write equation for motion of an object
OBJECT (NOT COMBINED) mass * a (a is unknown) = +-T (depending if it’s under g or not, T points always to the pulley) +- X. X could be the mass * g (if it’s under gravity) or if it’s on something then it’s the resistive forces (or just 0 if none)
Improvements which can be made to a model
BETTER ACCURACY FOR g
Variable resistance
Include dimensions of the objects (give an object, eg the ball)
What is the critical region
Region to accept alt hyp
How to find actual significance level
The values for the critical regions added (for two tail) as a percentage
For finding critical region, use equal and greater/less operands or just >. < without the equals
WITH the equals always
Asterisk on box plot
Outlier
AS level distributions TYPES
uniform discrete
continuous etc
AS level distribution MODELS
binomial
how to answer ‘why is this not a suitable model.. etc’ o.e.
X may not be proportional to Y
X may be affected by other things like ….
Binomial requirements
independent
Fixed size sample
Two outcomes
Sampling frame
Set of people/things which can be included in the sample
What is a statistic
Random variable that is a function of the sample with contains NO unknown params
Census vs sample
Census includes everyone in a population
Sample is a sample
What dates large data set
May to Oct 87,2015
