Definitions

Question 1

population

Answer 1

item of interest

Question 2

census

Answer 2

everyone in the population

Question 3

random sample

Answer 3

sampling in a non biased way

Question 4

stratified sample

Answer 4

grouped into strata by demographic

Question 5

parameter

Answer 5

used to describe the whole population

Question 6

two types of non random sampling

Answer 6

Quota and opportunity

Question 7

quota sampling

Answer 7

Decide how many members in each group and then use opportunity sampling

Question 8

Opportunity sampling

Answer 8

Taking samples from members of the population you have access to until you have your full sample size

Question 9

Quantitative data

Answer 9

associated with numerical observations

Question 10

Qualitative data

Answer 10

non numerical observations

Question 11

continuous data

Answer 11

Any value (measuring)

Question 12

discrete data

Answer 12

count (set numbers)

Question 13

Mode

Answer 13

most common

Question 14

Median

Answer 14

Middle

Question 15

Mean

Answer 15

Add all together and divide by amount

Question 16

Sum of data values

Answer 16

Mean X amount

Question 17

Interpercentile

Answer 17

x/100

Question 18

Interdecile

Answer 18

x/10

Question 19

linear interpolation

Answer 19

Finding the exact median

Question 20

standard deviation

Answer 20

square root of variance

Question 21

variance

Answer 21

mean of the squares - square of the mean

Question 22

coding

Answer 22

A way of simplifying statistical solutions

Question 23

Bar chart

Answer 23

frequency

Question 24

Pie chart

Answer 24

proportion

Question 25

outlier

Answer 25

values that lie significantly outside the set of values of the variable

Question 26

outliers removed

Answer 26

cleaning the data

Question 27

4 words to describe correlation

Answer 27

positive negative strong weak

Question 28

bivariate

Answer 28

each item requires the values of two variables

Question 29

dependent

Answer 29

measure Y axis

Question 30

Independent

Answer 30

control x axis

Question 31

spurious correlation

Answer 31

correlation without a causal connection

Question 32

PMCC

Answer 32

measure of the strength of the correlation

Question 33

least squares regression line

Answer 33

Minimises the sum of the squares of the distances of each data point from the line

Question 34

Residual

Answer 34

diet between data point and line of best fit

Question 35

A ∩ B

Answer 35

"a intersects b" - middle only

Question 36

A ∪ B

Answer 36

"A union B" - both whole circles

Question 37

A'

Answer 37

"Compliment of A" - everything except A and middle

Question 38

(A∩B')

Answer 38

A not including middle

Question 39

(A∪B)'

Answer 39

whole of outside

Question 40

(A'∩B)

Answer 40

just B without middle

Question 41

(A'∩B')

Answer 41

whole of outside

Question 42

(A∪B')

Answer 42

Everything except B and middle

Question 43

Mutually exclusive

Answer 43

two things that can't happen at the same time

Question 44

Independent events

Answer 44

One event has no effect on the other

Question 45

tree diagrams show

Answer 45

the outcome of two successive events

Question 46

Can model x with a binomial distribution if (4)

Answer 46

1. There are two possible outcomes 2. There are a fixed number of trials 3. Trials and independent of eachother 4. Probability for success is constant

Question 47

Cumulative probability function

Answer 47

Tells you sum of all individual probabilities up to and including x

Question 48

greater than 5 - X > 5

Answer 48

1 - P(X ≤ 5)

Question 49

No more than 3 - X ≤ 3

Answer 49

P(X ≤ 3)

Question 50

at least 7 - X ≥ 7

Answer 50

1 - P(X ≤ 6)

Question 51

fewer than 10 - X < 10

Answer 51

P(X ≤ 9)

Question 52

at most 8 - X ≤ 8

Answer 52

P(X ≤ 8)

Question 53

Hypothesis

Answer 53

population parameter statement

Question 54

Test statistic

Answer 54

Result of the hypothesis testing

Question 55

Null hypothesis H0

Answer 55

The default position - no biased, nothing changes

Question 56

Alternative hypothesis H1

Answer 56

A change - assumption shown to be wrong

Question 57

One tailed | either P>X or p

Answer 57

States there will be a change in a specified direction - eg. biased towards heads

Question 58

Two tailed | P ≠ X

Answer 58

there has been a change but in no specific direction - eg biased

Question 59

significance level

Answer 59

Cut off point - after this, can rule out the null hypothesis

Question 60

null hypothesis can't be ruled out

Answer 60

Insufficient evidence to reject the null

Question 61

critical region

Answer 61

A region which if the test statistic falls within it, would cause you to reject the null hypothesis

Question 62

critical value

Answer 62

First value to fall inside the critical region

Question 63

P value

Answer 63

Actual significance level

Question 64

Acceptance region

Answer 64

Set of values which cause you to accept the null hypothesis

Question 65

Probability distributon

Answer 65

A table/equation that links each outcome of a statistical experiment with its probability of occurrence

Question 66

Testing a hypothesis test (5)

Answer 66

1. State random variable (X) in words 2. State null and alternative hypothesis 3. Find P 4. Compare to significance level 5. Concluding statement