The marks obtained by students in a class test were

$\table 4,8,7,6,7;2,1,7,4,7;3,7,8,4,3;7,5,2,7,2;5,4,8,3,2$

(a) construct a frequency distribution table for the data.

(b) Find the:
(i) mode of the distribution;
(ii) median mark of the test;
(iii) mean mark.