Histograms and cumulative frequency

Question 1

What is formula of frequency density

Answer 1

Frequency / Clara width

Question 2

For is formula for median, lower quartile and upper quartile

Answer 2

N is number of numbers in list
Median = (n+1)/2
Lower quartile = (n+1)/4
Upper quartile =3(n+1)/4

Question 3

What is cumulative frequency

Answer 3

A running total worked out by adding the frequency of a class to the previous class cumulative frequency e,g,
Length frequency cumulative frequency
21-24. 3. 3
25-28. 7. 7+3=10
29-38. 12. 12+10=22

Question 4

Rule of drawing cumulative frequency graph

Answer 4

Always draw on the upper bound of the class
Use cumulative frequency on y axis

Question 5

What is the upper bound of

21-24 25-28 29-32

Answer 5

24.5 28.5 32.5

Question 6

How do you work out quartiles and median on cumulative frequency graph

Answer 6

Find quartiles on the y axis and lower read on the x axis. Interquartile range is upper - lower

Question 7

What are the parts of a bow and whisker plot

Answer 7

Left line ends on lowest value
Right line ends on highest value
From left to right first vertical line is lower quartile
Second is median
Third is upper quartile