The lengths (l

l

) in centimetres of 100

100

 copper pipes at a local building supplier were measured. The results are listed in the table below.

Write down the mode.

[1]
a.

Using your graphic display calculator, write down the value of
(i)     the mean;
(ii)    the standard deviation;
(iii)   the median.

[4]
b.

Find the interquartile range.

[2]
c.

Draw a box and whisker diagram for this data, on graph paper, using a scale of 1 cm

1 cm

 to represent 5 cm

5 cm

.

[4]
d.

Sam estimated the value of the mean of the measured lengths to be 43 cm

43 cm

.

Find the percentage error of Sam’s estimated mean.

[2]
e.

1. Vertical line test