Question

Find mean, median, mode: daily income(in rupees): 275, 325,375,425,475 . no.of workers: 12, 14,8,6,10​

Answer 1

Mean=

f

i

∑f

i

x

i

=

50

7260

=145.2

⇒ We have, N=50. Then,

2

N

=25.

⇒ Median class is 120−140

l= lower limit of the modal class

h= size of the class intervals

f= frequency of the modal class

f

1

= frequency of the class preceding the modal class

f

2

= frequency of the class succeed in the modal class.

⇒ So, l=120,h=20,N=50cf=12,f=14.

Median=l+

f

2

N

−cf

×h

⇒ Median=120+

14

25−12

×20

⇒ Median=120+

7

130

∴ Median=120+18.6=138.6

⇒ Modal class =120−140

⇒ l=120,f=14f

1

=12,f

2

=8,h=20

⇒ Mode=l+

2f−f

1

−f

2

f−f

1

×h

⇒ Mode=120+

2×14−12−8

14−12

×20

⇒ Mode=120+

8

40

∴ Mode=125