representation of data

Question 1

median ( odd)

Answer 1

Question 2

median (even)

Answer 2

Question 3

why is mean not suitable

Answer 3

because there’s an extreme value () which can affect the final average

Question 4

why is mode not suitable?

Answer 4

mode is not suitable as it will be the lowest/highest value () which can affect the interpretation of data

Question 5

LQ

Answer 5

1/4 *n

Question 6

UQ

Answer 6

3/4*n

Question 7

IQR

Answer 7

Q3-Q1

Question 8

2 comparisons

Answer 8

On Average (median/mean/mode) , compare using higher than, greater than, more than or less than
Range/IQR- more spread, less spread

Question 9

always label stem and leaf

Answer 9

in diagrams and write key

Question 10

standard deviation

Answer 10

always 3sf

Question 11

mean for ungrouped

Answer 11

Question 12

the standard deviation for ungrouped

Answer 12

Question 13

mean for grouped

Answer 13

Question 14

the standard deviation for grouped

Answer 14

Question 15

variation is

Answer 15

sd^2

Question 16

outliers

Answer 16

Q1-(1.5* IQR)
Q3+(1.5* IQR)
the numbers more than or less than these are the outliers

Question 17

explain why the mean is only an estimate

Answer 17

• mean can only be an estimate because we do not know the individual measurement of _. all the data has been grouped so we can only roughly estimate the mean for the grouped data.

Question 18

advantages of the cumulative frequency graph

Answer 18

• suitable for continuous data
• median, lower quartile, and upper quartile can be estimated from the graph
• sets of data can be compared by drawing graphs on the same diagram

Question 19

disadvantages of the cumulative frequency graph

Answer 19

it doesn’t show each data drawn from a grouped frequency table. the visual impact can be altered by choosing different groups

Question 20

advantages of histogram

Answer 20

suitable for continuous data
shows whether the distribution is symmetrical or skewed

Question 21

disadvantages of histogram

Answer 21

it dosent show each data as it is constructed from a grouped frequency table.
the visual impact can be altered by choosing different groups
two distributions cannot be shown on the same diagrams

Question 22

advantages of stem and leaf

Answer 22

• shows all the original data
• median, mode and quartiles can be found from the diagram

Question 23

disadvantages of stem and leaf diagrams

Answer 23

not suitable for a large set of data

Question 24

advantages of box and whisker plot

Answer 24

• easy to see whether the distribution is symmetrical or skewed
• median. lower quartile and upper quartile can be seen from the graph
• sets of data can be compared by drawing box and whisker plots on the same diagram

Question 25

disadvantages of box and whisker plots

Answer 25

it doesn't show each data

Question 26

Answer 26

negatively skewed

Question 27

Answer 27

positively skewed

Question 28

Answer 28

positively skewed

Question 29

Answer 29

negatively skewed

Question 30

in histogram the y axis is

Answer 30

f.d

Question 31

f.d=

Answer 31

f/c.w

Question 32

what assumption needs to be made for the estimate to become accurate

Answer 32

data is evely distrbuted within each class