Question

The mark obtained by the students in a class test are given below: 
31, 12, 28, 45, 32, 16, 49, 12, 18, 26, 34, 39, 29, 28, 25, 46, 32, 13, 14, 26, 25, 34, 23, 23, 25, 45, 33, 22, 18, 37, 26, 19, 20, 30, 28, 38, 42, 21, 36, 19, 20, 40, 48, 15, 46, 26, 23, 33, 47, 40.

Arrange the above marks in classes each with a class size of 5 and answer the following:
(i) what is the highest score?
(ii) What is the lowest score?
(iii) What is the range?
(iv) If the pass mark is 20, how many students failed/
(v) How many students got 40 or more marks?

Answer 1

CLASS	TALLY MARKS	FREQUENCY
11 - 15	IIII	5
16 - 20	IIII II	7
21- 25	IIII III	8
26 - 30	IIII IIII	9
31 - 35	IIII II	7
36 - 40	IIII I	6
41 - 45	III	3
46 - 50	IIII	5
	Total	50

(i) The highest score is 49.
(ii) The lowest score is 12.
(iii) Range = 49 - 12 = 37.
(iv) Given, pass marks is 20
So, all the students in the class 11 - 15 and 16 - 20 must have failed expect for the students with score 20.
∴ Number of such students = 5 + 7 - 2 = 10
(v) Number of students scoring above 40 is the sum total of students in the classes 41 - 45 and 46 - 50
i.e. 3 + 5 = 8
Number of students scoring exactly 40 = 2
∴ Number of students scoring 40 or more marks = 8 + 2 = 10.