paper 1 - analysis of data

Question 1

define population

Answer 1

consists of all members in the group being considered

Question 2

define representative

Answer 2

reflecting the whole population

Question 3

define discrete data

Answer 3

can take only an exact value

Question 4

define continuous

Answer 4

data can take any value in a range

Question 5

define qualititative

Answer 5

descriptive

Question 6

define quantitative

Answer 6

numerical and may be discrete or continuous

Question 7

define random sampling

Answer 7

equal chance of being chosen, e.g. drawing names out of a hat

Question 8

define systematic sampling

Answer 8

a starting point is chosen then every nth is selected

Question 9

pros of systematic sampling

Answer 9

simpler and quicker

Question 10

cons of systematic sampling

Answer 10

• may be unrepresentative if theres a pattern

- not equal chance of selection

Question 11

define quota sampling

Answer 11

population is divided into groups a given number is surveyed from each group

Question 12

cons of quota sampling

Answer 12

not random

Question 13

pros of quota sampling

Answer 13

cheap and quick to carry out

Question 14

define stratified sample

Answer 14

population is divided into quotas then sample is chosen from each category - sample is in proportion to size of each category in population

Question 15

define convenience sample

Answer 15

could be the first x number of people the interviewer meets

Question 16

pros of convenience sample

Answer 16

quick and cheap

Question 17

cons of convenience sample

Answer 17

highly likely the sample is unbiased or unrepresentative

Question 18

define cluster sample

Answer 18

population is divided into groups or clusters - group is chosen and every item in this group is chosen

Question 19

pros of cluster sample

Answer 19

a large number of small clusters minimises the chances of being unrepresentative

Question 20

define opinion polls

Answer 20

large scale opinion polls often use a combination of cluster and quota sampling

Question 21

pros of opinion polls

Answer 21

not biased

Question 22

cons of opinion polls

Answer 22

• disadvantage of conclusions drawn from opinion polls is that opinions may change over time
• large population but often based on a small proportion of the population

Question 23

how to find the interquartile range

Answer 23

IQR = UQ - UQ

Question 24

advantages of the range

Answer 24

easy to find

Question 25

disadvantages of the range

Answer 25

affected by extreme values

do not use all of the values of the data

Question 26

advantages of IQR

Answer 26

not affected by extreme values

Question 27

disadvantages of IQR

Answer 27

does not use all of the data

may not give a fair comparison if one dataset has more values than the others

Question 28

advantages of standard deviation

Answer 28

uses all of the data

gives a fair comparison when one dataset has more values than the other

Question 29

disadvantages of standard deviation

Answer 29

more difficult to calculate

Question 30

to draw a histogram 2

Answer 30

• subtract class boundary to find class width

- if not equal , divide each frequency by class width to give frequency.