Question

19. (i) Find the class mark of the class 90–120.
(ii) In a frequency distribution, the mid-value of the class is 10 and
width of the class is 6. Find the lower limit of the class.
(iii) The width of each of five continuous classes in a frequency
distribution is 5 and lower class limit of the lowest class is 10. What
is the upper class limit of the highest class?
(iv) The class marks of a frequency distribution are 15, 20, 25, ... . Find
the class corresponding to the class mark 20.
(v) In the class intervals 10–20, 20–30, find the class in which 20 is
included.​

Answer 1

1. 105
2. 7

Step-by-step explanation:

90+120/2=105

x+y/2=10

x+y=20

x-y=6

2x=26

x=13

y=7