Stats year 1

Question 1

Define population

Answer 1

A complete set of data where every element is included

Question 2

Define sample

Answer 2

A selection of the population

Question 3

Define census

Answer 3

why is it rare?

Question 4

Define sampling units

Answer 4

These are the elements of data in a sample

Question 5

Define sampling frame

Answer 5

A list of sampling units

Question 6

Define random sampling methods

Answer 6

Every element of the population has an equal chance of being selected

Question 7

What are the 3 random sampling methods?

Answer 7

Simple random sample

Question 8

Define simple random sample

Answer 8

Using random numbers or ‘names out of a hat’

Question 9

Define systematic sample

Answer 9

All elements numbered

Question 10

Define stratified sampling

Answer 10

The proportion of groups in the population are represented in the survey

Question 11

What is the danger of non-random sampling?

Answer 11

Bias

Question 12

Define opportunity sampling

Answer 12

Your sample is whoever turns up

Question 13

Define quota sampling

Answer 13

Numbers are calculated for each group then when groups are filled

Question 14

Define qualitative data with examples

Answer 14

Groups of data

Question 15

Define quantitative data with examples

Answer 15

Numerical data

Question 16

What two types of data can quantitative data be sectioned into?

Answer 16

Discrete and continuous

Question 17

What is discrete data?

Answer 17

Whole numbers

Question 18

What is continuous data?

Answer 18

Data that can take any value

Question 19

What does n/a mean?

Answer 19

Not available

Question 20

If one cell of data has n/a in it

Answer 20

what should you do to the whole row?

Question 21

What does tr mean?

Answer 21

Trace

Question 22

If a cell of data has tr in it what should you do to it? Why?

Answer 22

Assume it’s 0
Because it means anything less than 0.05(near 0)

Question 23

How is daily mean temperature measured?

Answer 23

Values are noted in degrees (Celsius) and tenths

Question 24

What is the daily mean temperature?

Answer 24

The average of the hourly air temperature readings during the period 0900-0900 GMT

Question 25

How is daily total rainfall measured?

Answer 25

Millimetres (mm)

Question 26

What is daily total rainfall?

Answer 26

24-hour periods commencing at 0900 GMT on the day of entry and includes any solid precipitation

Question 27

How is daily total sunshine measured?

Answer 27

In hours and tenths

Question 28

What is daily total sunshine?

Answer 28

The amount of bright sunshine recorded on the day of entry

Question 29

How is daily maximum relative humidity measured?

Answer 29

As a percentage

Question 30

What is daily maximum relative humidity?

Answer 30

A measure of how close the air is to being saturated with water vapour. Values greater than 95% are associated with mist and fog

Question 31

How is wind speed measured?

Answer 31

Knots

Question 32

What is knots to mph?

Answer 32

1 knot = 1.15 mph

Question 33

How is the daily mean wind speed measured?

Answer 33

Averaged over the 24 hours from 0000GMT on the date given

Question 34

What is maximum gust speed?

Answer 34

The maximum instantaneous speed that occurred during the 24 hours from 0000GMT on the date given

Question 35

How is the daily mean wind direction measured?

Answer 35

Averaged over the 24 hours from 0000GMT on the date given

Question 36

How is daily maximum gust direction measured?

Answer 36

In degrees from true north

Question 37

What is daily maximum gust direction?

Answer 37

The direction from which the wind was blowing when the maximum gust during the hour commencing at the time of entry occurred

Question 38

What is cloud cover?

Answer 38

The fraction of the celestial dome covered by cloud

Question 39

How is cloud cover measured?

Answer 39

Measured in eighths (Oktas)

Question 40

What is visibility?

Answer 40

The greatest distance at which an object can be seen and recognized in daylight

Question 41

How is visibility measured?

Answer 41

Measured horizontally

Question 42

How is pressure measured?

Answer 42

By the SI unit of pressure

Question 43

Which station is the furthest north?

Answer 43

Leuchars

Question 44

Which station is the furthest south?

Answer 44

Perth

Question 45

Describe where Leuchars is

Answer 45

A coastal station far north in Scotland

Question 46

Describe where Leeming is

Answer 46

An inland station in Northern England

Question 47

Describe where Heathrow is

Answer 47

An inland station in Southern England

Question 48

Describe where Hurn is

Answer 48

A coastal station in Southern England

Question 49

Describe where Camborne is

Answer 49

A coastal station in South West England

Question 50

Describe where Jacksonville is

Answer 50

An overseas coastal station in South East USA

Question 51

Describe where Perth is

Answer 51

An overseas coastal station in South West Australia

Question 52

Describe where Beijing is

Answer 52

An overseas inland station in Eastern China

Question 53

What is better

Answer 53

range or IQR?

Question 54

What is variance?

Answer 54

A calculation of spread using every piece of data

Question 55

Standard deviation is the ____ _____ of variance

Answer 55

Square root

Question 56

Does the mean of squares = the square of means?

Answer 56

No

Question 57

Variance =

Answer 57

Mean of squares - square of means

Question 58

Symbols for variance and standard deviation

Answer 58

σ for standard deviation and σ^2 for variance

Question 59

What does an x with a bar on top mean?

Answer 59

The mean of x

Question 60

Variance equation

Answer 60

((Σ(x^2))/n) - ((Σx)/n)^2

Question 61

Standard deviation equation

Answer 61

Root(((Σ(x^2))/n) - ((Σx)/n)^2)

Question 62

How does coding by +/- affect mean?

Answer 62

If y = x - a

Question 63

How does coding by x/÷ affect mean?

Answer 63

If y = x/b

Question 64

How does coding by +/- affect standard deviation?

Answer 64

If y = x - a

Question 65

How does coding by x/÷ affect standard deviation?

Answer 65

If y = x/b

Question 66

Another way to write variance

Answer 66

Variance = (sxx)/n

Question 67

Probability rule for mutually exclusive events

Answer 67

P(A or B) = P(A) + P(B)

Question 68

Probability rule for independent events

Answer 68

P(A and B) = P(A) x P(B)

Question 69

Define random variable

Answer 69

A variable whose value depends on the outcome of a random event

Question 70

Define sample space

Answer 70

The range of values that a random variable can take

Question 71

What makes a variable random?

Answer 71

If the outcome is not known until the experiment is carried out

Question 72

What does a probability distribution do?

Answer 72

Fully describes the probability of any outcome in the sample space

Question 73

What is a discrete uniform distribution?

Answer 73

When all of the possibilities are the same

Question 74

sum of P(X=x) =

Answer 74

1

Question 75

Binomial distribution

Answer 75

B(n

Question 76

Binomial distribution formula

Answer 76

(n choose r)(p^r)((1-p)^(n-r))

Question 77

What symbol is the index?

Answer 77

n

Question 78

What symbol is the parameter?

Answer 78

p

Question 79

When can you model x with a binomial distribution?

Answer 79

Fixed number of trials

Question 80

What does a cumulative probability function do?

Answer 80

Tells you the sum of all the individual probabilities up to and including the given value

Question 81

What is a hypothesis test?

Answer 81

A statement made about the value of a population parameter

Question 82

What is the null hypothesis?

Answer 82

H0

Question 83

What is the alternative hypothesis?

Answer 83

H1

Question 84

One-tailed tests are

Answer 84

When your alternative hypothesis is in the form > or <

Question 85

Two-tailed tests are

Answer 85

When your alternative hypothesis is in the form ≠

Question 86

When do you reject the null hypothesis?

Answer 86

If likelihood < significance level

Question 87

A critical region is

Answer 87

A region where

Question 88

The critical value is

Answer 88

The first value to fall inside the critical region

Question 89

What must you do to the significance level in a two-tailed test?

Answer 89

Halve it