Question

19.
There are three sections of class X in Kendriya Vidyalaya, Delhi Cantt. The total
number of students in class tenth are 100. The marks obtained by the students in
Preboard exam are presented in a table as given below. The mean of the marks
obtained is 53.
Marks obtained 0-20 20 - 40 40 - 60 | 60 - 80
80 - 100
No. of students
15
18
21
29
р
(i)
How many students got marks between 80 - 100?
a) 21
b) 38
c) 17
d) 26
(ii)
What is the lower limit of modal class ?
a) 20
b) 40
c) 60
d) 80
(iii)
What is the value of modal marks?
b) 62
a) 58
c) 65
d) 68
(iv)
What is the value of fixi?
a) 2900
b) 5300
c) 1500
d) 100
(V)
What is the upper limit of the median class?
b) 40
c) 60
d) 80
a) 20​

Answer 1

Answer:

rperson come mz-jfjj-jid only show type

Answer 2

Given :

Marks obtained=   0-20,20-40,40-60,60-80,80-100

Number of student   15  ,  18,       21,       29,        p

mean of the marks obtained is 53

To Find : (1) how many students got marks between 80-100?

a)21 (b)38 (c) 17 (d)26 (2)

what is the lower limit of modal class a)20 (b)40 (c)60 (d) 80  

what is the value of modal marks

(a)58 (b)62 (c) 65 (d) 68  

what is the value of {fixi? (a)2900 (b) 5300 (c) 1500 (d) 100

what is the upper limit of the median class?

(a) 20 (b) 40 (c) 60 (d) 80

Solution:

Marks obtained class mark x         f             fixi

0-20,                       10                    15            150          

20-40,                    30                    18            540    

40-60,                    50                    21           1050    

60-80,                    70                    29          2030    

80-100                   90                    p             90p

                         Total                  83+p        3770 + 90p

Mean = (3770 + 90p)/(83   + p)  = 53

=> 3770 + 90p = 83 * 53 + 53p

=> 37p  = 629

=> p = 17

17 students got marks between 80-100

Modal class 60-80   with f = 29

lower limit of modal class 60

Mode = 60 + 20 * (29 - 21)/(29 - 21 + 29 - 17)

= 60 + 20 * 8/20

= 68

value of modal marks = 68  

∑fixi  =  3770 + 90p  = 3770 + 90(17) = 5300

83 + p = 83 + 17 = 100

100/2 = 50

15 + 18 + 21 = 54 > 50

Median class = 40-60

upper limit of the median class 60

Learn More:

the mean, median and the mode for the following data series: 18, 20 ...

brainly.in/question/9098099

The median and modal profits for the following data Profit in '000 ...

brainly.in/question/11976434

Which relation among three measures of central tendency, mean ...

brainly.in/question/23859903