Question

The median of the given frequency distribution is 14.4 and the sum of all frequencies is 20. Find the values of p and q

Answer 1

Answer:

Class Interval Frequency midpoint (x) Comm frequecy

0-6 4 3 4

6-12 x 9 4+x

12-18 5 15 9+x

18-24 y 21 9+x+y

24-30 1 27 10+x+y

Total 20

∑f=20

x+y=10−−−−−−−−−−(1)

Median is 14.4

S0, Median class is 12−18

Median =L+

f

2

n

−C

×w

So 14.4=12+

5

2

20

−(4+x)

×6

14.4×5=60+(10−4−x)×6

72=60+60−24−6x

6x=120−24−72

6x=120−96

6x=24

x=4

from eq (1)

4+y=10⇒y=6

Answer 2

Answer:

x+y+10=20

x+y=10

14.4=12+(10-4-x/5).6

72=60+(6-x). 6

72-60=36-6x

12-36=-6x

-24=-6x

;x=4

y=6