Nine years * * * class of 60 people;
(2) The number of "Class C" students is 60× 15%=9 (people),
The number of people with grade "D" is 60-3-30-9= 18 (people).
The complete statistical chart of broken lines is as follows:
(3) 108 ;
(4) × 100%=5%,
The excellent rate of this class is 5%.