Answer:
a) The relative frequencies of grade A,B,C,D,F are 0.2, 0.3, 0.2, 0.15, 0.15 respectively.
b) Grade B recieved the most students.
Explanation:
a) The relative frequency of an event is defined as the number of times that the event occurs during experimental trials, divided by the total number of trials conducted.
In this case, total numbers of trials indicates total number of students(20).
Therefore,
The relative frequency of A is
.
The relative frequency of B is
.
The relative frequency of C is
.
The relative frequency of D is
.
The relative frequency of F is
.
b) The grade with the most students recieve is the one with highest relative frequency.
Hence, Grade B recieved the most students.