Question

marks obtained 15 17 20 22 25 30 no. of students 2 5 10 12 8 4 find median mode mean​

Answer 1

Answer:

Answer

Marks Mid−value

x

i

No.offrequency

f

i

c.f f

i

x

i

0−10 5 1 1 5

10−20 15 4 5 60

20−30 25 5 10 125

30−40 35 8 18 280

40−50 45 2 20 90

∑f

i

=20 ∑f

i

x

i

=560

⇒ Mean(

x

)=

∑f

i

∑f

i

x

i

=

20

560

=28

⇒ Modal class =30−40

So, l=30,f

0

=5,f

1

=8,f

2

=2 and h=10

⇒ Mode=l+

2f

1

−f

0

−f

2

f

1

−f

0

×h

=30+

2×8−5−2

8−5

×10

=30+3.33

∴ Mode=33.33

⇒ Here, n=20, then

2

n

=

2

20

=10

∴ Median class =20−30

So, c.f=5,f=5,l=20 and h=10

⇒ Median=l+

f

2

N

−c.f

×h

=20+

5

10−5

×10

=20+10

∴ Median=30

Step-by-step explanation:

Marks 0−10 10−20 20−30 30−40 40−50

No. of students 1 4 5 8 2