statistics

studied byStudied by 6 people
0.0(0)
Get a hint
Hint

Population

1 / 49

50 Terms

1

Population

The whole set of items that are of interest

New cards
2

Census

Observes or measures every member of a population

New cards
3

Advantages of a census

It should give a completely accurate result

New cards
4

Disadvantage of a census

Time consuming and expensive Hard to process large quantity of data

New cards
5

Sample

A selection of observations taken from a subset of the population which is used to find out information about the population as a whole

New cards
6

Advantages of a sample

Less time consuming Fewer people have to respond Less data than a census

New cards
7

Disadvantage of a sample

The data may not be as accurate The data may not be large enough toggle information about the population

New cards
8

Sampling Units

Individual units of a population

New cards
9

Sampling Frame

A list of individually named or numbered sampling units

New cards
10

Simple Random Sample

A sample where every sampling unit has an equal chance of being chosen

New cards
11

Advantages of Simple Random Sample

Free of bias Easy and cheap to implement Each sampling unit has equal chance of selection

New cards
12

Disadvantage of Simple Random Sample

A sampling frame is needed Not suitable when the population size is very big

New cards
13

Systematic Sampling

A method of sampling where the required elements are chosen at regular intervals from an ordered list

New cards
14

Advantages of Systematic Sampling

Simple and quick to use Suitable for large samples

New cards
15

Disadvantages of Systematic Sampling

A sampling frame is needed It can introduce bias if sampling frame is not random

New cards
16

advantages of Stratified Sampling

Sample accuracy reflects the population structure guarantees proportional representation of groups within a population

New cards
17

Disadvantages of Stratified Sampling

Population must be classified into distinct strata

Selection within each stratum can be time consuming and expensive if sample size is large

A sampling frame is needed

New cards
18

Stratified Sampling

A method of sampling where the population is divided into mutually exclusive strata and a random sample is taken from each

New cards
19

The number sampled in a stratum

(Number in stratum/number in population)* overall sample size

New cards
20

Quota Sampling

A method of sampling where a researcher selects a sample that reflects the characteristics of the whole population

New cards
21

Advantages of Quota Sampling

Allows a small sample to still represent the whole population No sampling frame required Quick, easy and inexpensive Allows for easy comparison between different groups in the population

New cards
22

Disadvantages of Quota Sampling

Not random sampling can produce bias Population must be divided into groups which can be costly or inaccurate Non-responces are recorded as such

New cards
23

Opportunity Sampling

A method of sampling where the people sampled are those who are available at the time the study is carried out and who fit the criteria you are looking for

New cards
24

Advantages of Opportunity Sampling

Easy to carry out Inexpensive

New cards
25

Disadvantages of Opportunity Sampling

Unlikely to provide a representative sample Highly dependent on individual researcher

New cards
26

Quantitative Variables/Data

Variables or data associated with numerical observations

New cards
27

Qualitative Variables/Data

Variables or data associated with non-numerical observations

New cards
28

Continuous Variable

A variable that can take any value in a given range

New cards
29

Discrete Variable

A variable that can take only specific values in a given range

New cards
30

Class Boundaries

The maximum and minimum values that belong in each class

New cards
31

Midpoint

The average of the class boundaries

New cards
32

Class Width

The difference between the upper and lower class boundaries

New cards
33

Interpercentile range

The difference between the values for 2 given percentiles.

New cards
34

Cleaning the data

The process of removing anomalies from a data set.

New cards
35

bivariate data

Data which has pairs of values for two variables

New cards
36

Correlation

A measure of the linear relationship between two variables

New cards
37

regression line

a line of best fit, y = a+bx

New cards
38

mutually exclusive events

events that have no sample points in common , P(A or B) = P(A) + P(B)

New cards
39

independent events

The outcome of one event does not affect the outcome of the second event , P(A and B) = P(A) x P(B)

New cards
40

tree diagram

A diagram used to show the total number of possible outcomes

New cards
41

probability distribution

Describes the probability of any outcome in the sample space.

New cards
42

binomial distribution

When there are a fixed number of trials There are 2 possible outcomes (success or failure) There is a fixed probability of success The trials are independent of each other

New cards
43

the null hypothesis

The hypothesis you assume to be correct

New cards
44

alternative hypothesis

Tells us about the parameter if your assumption is wrong

New cards
45

critical region

the area in the tails of the comparison distribution in which the null hypothesis can be rejected

New cards
46

mutually exclusive

Events have no outcomes in common, they can't happen at the same time

New cards
47

independent

When one event has no effect on another

New cards
48

If events A and B are independent…

P(A intersection B)= P(A)x P(B)

P(A|B)=P(A)

New cards
49

If events A and B are mutually exclusive

P(A intersection B)= 0

P(A union B)= P(A)+P(B)

New cards
50

When A and B are not mutually exclusive, P(A union B)=

P(A)+ P(B)- P(A intersection B)

New cards

Explore top notes

note Note
studied byStudied by 5 people
... ago
5.0(1)
note Note
studied byStudied by 637 people
... ago
5.0(1)
note Note
studied byStudied by 9 people
... ago
5.0(1)
note Note
studied byStudied by 4637 people
... ago
5.0(1)
note Note
studied byStudied by 82 people
... ago
5.0(2)
note Note
studied byStudied by 92 people
... ago
5.0(1)
note Note
studied byStudied by 109 people
... ago
5.0(3)
note Note
studied byStudied by 635 people
... ago
5.0(3)

Explore top flashcards

flashcards Flashcard (65)
studied byStudied by 59 people
... ago
5.0(2)
flashcards Flashcard (206)
studied byStudied by 11 people
... ago
5.0(1)
flashcards Flashcard (120)
studied byStudied by 16 people
... ago
5.0(1)
flashcards Flashcard (87)
studied byStudied by 74 people
... ago
4.5(2)
flashcards Flashcard (57)
studied byStudied by 70 people
... ago
5.0(1)
flashcards Flashcard (102)
studied byStudied by 7 people
... ago
5.0(1)
flashcards Flashcard (24)
studied byStudied by 23 people
... ago
4.9(8)
flashcards Flashcard (51)
studied byStudied by 2 people
... ago
5.0(1)
robot