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The mode of the following data is 154. Find the . . .

Question : The mode of the following data is 154. Find the value of m. Also find median of following data.

Class Intervals 120-130 130-140 140-150 150-160 160-170
Frequency 2 8 m 20
8

Doubt by Parth 

Solution : 

Mode = 154
Modal Class = 150-160
l=150
h=160-150=10
f0=m
f1=20
f2=8


Mode = l+{[f1-f0]/[2f1-f0-f2]}×h
154 = 150+{[20-m]/[2(20)-m-8]}×10
154-150= {[20-m]/[40-m-8]}×10
4/10 = {[20-m]/[32-m]}
2/5 = [20-m]/[32-m]
2[32-m] =5[20-m]
64-2m=100-5m
5m-2m=100-64
3m=36
m=36/3
m=12


Median of the Data 


Class Intervals (CI)  Frequency (fi) Cumulative Frequency (CF)
120-130 2 2
130-140 8 10
140-150 12 22
150-160 20 42
160-170 8 50

N=Σfi=50


Here 
N=Σfi=50
N/2 = 50/2 = 25
Median class = 150-160
l=150
h=160-150=10
CF=22
f=20

Median = l+{[(N/2)-CF]/[f]}×h
Median = 150+{[25-22]/[20]}×10
Median = 150+30/20
Medina = 150+3/2
Median = 150+1.5
Median = 151.5