If the median of the following frequency distribution is 46, find the missing frequencles, Class-interval Frequency
10-20 12
20-30 30
30-40 ?
40-50 65
50-60 ?
60-70 25
70-80 18
Total 229
Answers
Answer:
Step-by-step explanation:
Correct option is
A
P = 34, Q = 45
Class interval Frequency C.F.
10 - 20 12 12
20 - 30 30 42
30 - 40 f
1
42+f
1
40 - 50 65 107+f
1
50 - 60 f
2
107+f
1
+f
2
60 - 70 25 132+f
1
+f
2
70 - 80 18 150+f
1
+f
2
Let the frequency of the class 30 - 40 be f
1
and that of the calss 50 - 60 be f
2
The total frequency is 229
12 + 30 + f
1
+ 65 + f
2
+ 25 + 18 = 229 ⇒f
1
+f
2
=79
It is given that median is 46 clearly 46 lies in the class 40 - 50. So 40 - 50 is the median class
∴l=40,h=10,f=65andC=42+f
1
,N=229
Median = l+
f
2
N
−C
×h⇒46=40+
65
2
229
−(42+f
1
)
×10⇒46=40+
13
145−2f
1
⇒6=
13
145−2f
1
→2f
1
=67⇒f
1
=33.5or34 Since f
1
+f
2
=79∴f
2
=45 Hence f
1
=34 and f
2
=45
Given : frequency distribution is 46
To Find : missing frequencies
Solution:
CI f cf
10-20 12 12
20-30 30 42
30-40 x 42 + x
40-50 65 107 + x
50-60 y 107 + x + y
60-70 25 132 + x + y
70-80 18 150 + x + y
Total 229
150 + x + y = 229
=> x + y = 79
Median is 46 lies in 40 - 50
46 = 40 + 10 ( 229/2 - (42 + x)) / 65
=> 6 = ( 229 - 84 - 2x) /13
=> 78 = 145 - 2x
=> 2x = 67
=> x = 33.5
x + y = 79
=> y = 45.5
Missing frequencies are 33.5 and 45.5
Learn More:
AM is 29 .find the missing frequency .x-5,15,25,35,45,55,f-5,7
brainly.in/question/24128502
AM is 29 .find the missing frequency .x-5,15,25,35,45,55,f-5,7
brainly.in/question/24128533