(a)

x	0	1	2	3	4	5	Total
f	1	4	9	8	5	3	30
fx	0	4	18	24	20	15	81

(i) Mean(\(\bar{x}\) = \(\frac{\sum fx}{\sum f}\)
= \(\frac{81}{30}\)
= 2.7
(ii) \(N = \sum f = 30\)
\(median = \frac{1}{2}(N + 1)\)
= \(\frac{1}{2}(30 + 1)\)
=15.5
= The 15th and 16th position.
\(\therefore median = \frac{3 + 3}{2} = 3\)
(b) Sectorial angle for the mark 2 = \(\frac{9}{30} \times 360°\)
= 108°.