# STATS AND MECH Flashcards Preview

## EDEXCEL MATHS > STATS AND MECH > Flashcards

Flashcards in STATS AND MECH Deck (37)
1
Q

Daily mean temperature

A

Average temp readings for 24 hours

DEGREES

2
Q

Daily total rainfall

A

in mm
Trace is <0.05
0 when doing mean

3
Q

Daily total sunshine

A

Nearest tenth of an hour

It’s the amount bright sunshine

4
Q

Daily maximum relative humidity

A

% of air with water vapour

over 95 is fog

5
Q

Daily mean wind speed

A

In knots

In Beaufort scale

6
Q

1 knot in km

A

1.8

7
Q

Beaufort scale range

A

0 - calm
6 - strong breeze
12 - hurricane

8
Q

Daily maximum gust

A

Maximum wind speed in a day

In knots

9
Q

Daily mean wind direction

A

From north a bearing not padded with 0s

Rounded nearest 10

10
Q

Cloud cover

A

In oktas, fraction of sky covered by cloud

0-8

11
Q

Visibility

A

DECAMETERS (10cm)

Greatest distance an object can be seen in daylight

12
Q

Mean pressure

A
```Mean pressure at sea level
In hPa (100pa)```
13
Q

Typical pressure range

A

900-1100hPa

14
Q

Frequency, cw, density equation

A

freq = fd* cw

15
Q

How to prove statically independent

A

P(A) * P(B) == P(A n B)

16
Q

A

It is a piece of data and we should consider all the data

17
Q

A

It is an extreme value and could unduly influence the analysis

18
Q

How to answer give an interpretation of the correlation between X and Y

A

as X (in/decreases), Y (in/decreases)

19
Q

How to answer ‘give interpretation of regression line’

A

a X amount increase in X gives rise to a Y increase in Y

20
Q

How to answer comment on suitability of sampling method

A

Anything valid such as ‘could use from more locations/from more months’

21
Q

How to answer suggest how would better use the large data set

A

Use more locations and more of the months

22
Q

How to answer comment on validity of the model to obtain answer

A

RELATE the sampling type to the question, eg is the sample random?

23
Q

How to explain restriction in polynomial function (eg for some range of values of X)

A

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’

24
Q

How to write equation for motion of an object

A

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)

25
Q

Improvements which can be made to a model

A

BETTER ACCURACY FOR g
Variable resistance
Include dimensions of the objects (give an object, eg the ball)

26
Q

What is the critical region

A

Region to accept alt hyp

27
Q

How to find actual significance level

A

The values for the critical regions added (for two tail) as a percentage

28
Q

For finding critical region, use equal and greater/less operands or just >. < without the equals

A

WITH the equals always

29
Q

Asterisk on box plot

A

Outlier

30
Q

AS level distributions TYPES

A

uniform discrete

continuous etc

31
Q

AS level distribution MODELS

A

binomial

32
Q

how to answer ‘why is this not a suitable model.. etc’ o.e.

A

X may not be proportional to Y

X may be affected by other things like ….

33
Q

Binomial requirements

A

independent
Fixed size sample
Two outcomes

34
Q

Sampling frame

A

Set of people/things which can be included in the sample

35
Q

What is a statistic

A

Random variable that is a function of the sample with contains NO unknown params

36
Q

Census vs sample

A

Census includes everyone in a population

Sample is a sample

37
Q

What dates large data set

A

May to Oct 87,2015