11 The table shows some information about the heights of a group of adults.
least height
169 cm
greatest height
186 cm
median
177 cm
lower quartile
174 cm
upper quartile
180 cm
(a) On the grid, draw a box plot for the information in the table.(3)
The box plot below shows the distribution of the heights of a group of teenagers.
(b) Compare the distribution of the heights of the adults with the distribution of the heights of the teenagers. (2)
Mark scheme (a)
Answer
Mark
Mark scheme
Box plot
B3
for fully correct box plot
(B2
for box plot showing a box and whiskers and at least 3 correctly plotted values from 169, 174, 177, 180, 186)
(B1
for at least 2 correctly plotted values including a box or whiskers)
Additional guidance
Box can be of any height. Accept ends that are marked (eg line, cross, dot) or defined by the end of the whiskers if clear
Mark scheme (b)
Answer
Mark
Mark scheme
Comparisons
C1
(ft) for a correct comparison of medians, eg the median for Adults is greater than the median for Teenagers or the Teenagers heights are lower in general as the median is lower
C1
(ft) for a correct comparison of a measure of spread, eg the interquartile (range) of the Adults is the same as (similar to) the IQR of the Teenagers, the range of the Teenagers is greater than the range of the Adults Comparisons for this mark can relate to the range or the IQR.
Additional guidance
For 2 marks, at least one comparison must be in context (eg refers to heights or cm).
Simply quoting values for median and range and IQR is insufficient, they must be compared
Median
Range
IQR
Adults
177
17
6
Teenagers
169
20.5
6
Figures need not be seen but if given they must be correct.
