Question

From the frequency table with the help of the graph and find the mean score of 60,65,70,75,80,85,90,95,100

please tell answer with explaination​

Answer 1

Step-by-step explanation:

Converting the given data into a frequency distribution table

Maths marks No. of students

(f) c.f.

60−65 8 8

65−70 12 20

70−75 14 34

75−80 8 42

80−85 5 47

85−90 6 53

90−95 4 57

N=Σf=57

Here, N=57

⟹

2

N

=

2

57

=28.5

⟹In the above table 70−75 is the median class and the respective c.f. is 20 (cumulative frequency of the class preceding the median class)

Acc to ques,

l=70 (lower limit of median class)

c.f. =20

h=l

2

−l

1

=5 (width of class interval of median class)

f=14 (frequency of median class)

Median=l+

f

2

N

−c.f.

×h=70+

14

28.5−20

×5

⟹ Median =73.05