Page 17 - Math SL HB Sem 3

6.6 : BOX-AND \YEISKER-PLOTS

a A box-and whisker plot ( boxplot) is a visual display of some of the
descriptive statistics ofa data set.It shows:

) the minimum value (Min*) Known as five-
F the lower quartile (aD number summary
D the median (A)
F the upper quartile (a,
! the maximum value (Max)
a The general form ofa box-and-whisker plots:

Lowest L,ower median upper highest
value quartile quartile value

Example:
For the data set : 4,5,9,5,1,7,8,7 3,5,6,3,4,3 2,5.
(a) constuct the five-nt'mb'er zummary
(b) draw a boxplot
(c) find the (i) range (ii) interquartile range
(d) the percentage of data values above 3

Erample:
Ranji counts the number of bolts in several boxes and tabulates the data as shown below:

Number {t 34 35 36 37 38 39 40
ofbolts
lFrequency I 5 7 l3 12 8 0 I

(a) Find the five-number summary for this data sel
(b) Fiid ttte:
(D nmge
(ii) interquartile for this data set
(c) Construct a boxplot for the data set

aa