The mean of following frequency distribution is 63.3 and sum of all frequenices is 50.complete the missing frequency f1 and f2
class 0-20=frequency 5
class 20-40=frequency f1
class 40-60 =frequency 10
classb60-80=frequency f2
class 80-70 =frequency 7
100-120=8
Answers
Given : The mean of following frequency distribution is 63.3 and sum of all frequencies is 50.
class 0-20=frequency 5
class 20-40=frequency f1
class 40-60 =frequency 10
classb60-80=frequency f2
class 80-100 =frequency 7
100-120= =frequency8
To Find : the missing frequency f1 and f2
Solution:
Class mean d = (mean - 50)/20 f df
0 - 20 10 -2 5 -10
20 - 40 30 -1 f1 - f1
40 - 60 50 0 10 0
60 -80 70 1 f2 f2
80 - 100 90 2 7 14
100 - 120 110 3 8 24
Total 30 + f1 + f2 28 + f2 - f1
30 + f1 + f2 = 50
=> f1 + f2 = 20
Mean = 50 + 20 * (28 + f2 - f1)/50
=> 63.3 = 50 + 2 * (28 + f2 - f1)/5
=> 66.5 = 56 + 2( f2 - f1)
=> 10.5 = 2( f2 - f1)
=> f2 - f1 = 5.25
f1 + f2 = 20
f2 - f1 = 5.25
=> 2f2 = 25.25
=> f2 = 12.625
f1 = 7.375
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