Question

32
The median of the following data is 16. Find the missing
frequencies a and b, if the total of the frequencies is 70
CLASS
10-15 15 30 20315 125-10
12
b
B
FREQU 22
ENCY​

Answer 1

Answer: Here:

N=70

N/2=35

Median =16, Median class =15−20

So, I=15, h=5, f=15 and

xf=xf of preceding class i.e.24+a

We know,  

$l+(h*\frac{\frac{n}{2} -c.f}{f})$

Substitute all the value in the above formula, we get

16=15+{5×(35−24−a)/15}

⇒16=15+(11−a)/3

or a=8

Now, 70=55+a+b

70=55+8+b

⇒b=7

so, the missing frequencies are 8 and 7.