Question

Marks 0 and above 10 and above 20 and above 30 and abou 40 and above 50 and above Go and above to and above Number of students 80 77 72 65 55 43 28 16 80 and above 10 8 90 and above 100 and above 0 Write the proper data mgoles) and frequency (No. of students)​

Answer 1

Answer:

Here we have, the cumulative frequency distribution. So, first we convert it into an ordinary frequency distribution. we observe that are 80 students getting marks greater than or equal to 0 and 77 students have secured 10 and more marks. Therefore, the number of students getting marks between 0 and 10 is 80-77= 3.

Similarly, the number of students getting marks between 10 and 20 is 77-72= 5 and so on. Thus, we obtain the following frequency distribution.

Marks Number of students

0-10 3

10-20 5

20-30 7

30-40 10

40-50 12

50-60 15

60-70 12

70-80 6

80-90 2

90-100 8

Now, we compute mean arithmetic mean by taking 55 as the assumed mean.

Computative of Mean

Marks

(x

i

) Mid-value (f

i

) Frequency u

i

10

x

i

−55

f

i

u

i

0-10 5 3 -5 -15

10-20 15 5 -4 -20

20-30 25 7 -3 -21

30-40 35 10 -2 -20

40-50 45 12 -1 -20

50-60 55 15 0 0

60-70 65 12 1 12

70-80 75 6 2 12

80-90 85 2 3 6

90-100 95 8 4 32

Total

∑f

i

=80 ∑f

i

u

i

= -26

We have,

N= sumf

i

=80,∑f

i

u

i

=−26, A= 55 and h= 10

∴

X

=A+h[

N

1

∑f

i

u

i

]

⇒

X

=A+h[

N

1

∑f

i

u

i

]

⇒

X

=55+10×

80

−26

=55−3.25=51.75Marks.

Answer 2

$\blue{ \Large{\boxed{ \tt{ \red{Answer : }}}}}$

$\begin{table}{lclclc} \end{table}$

• Frequency => 5, 10, 15