Find the missing frequencies in the following frequency distribution if it is known that the mean of the distribution is 50.
Answers
Given frequency distribution :
x :
10 30 50 70 90
f:
17 f1 32 f2 19
Total 120
Solution :
From the table :
Σfixi = 3480 + 30f1 + 70f2 , Σfi = 68 + f1 + f2
Given : Σfi = 120 , Mean = 50
Σfi = 68 + f1 + f2
120 = 68 + f1 + f2
f1 + f2 = 120 - 68
f1 + f2 = 52
f1 = 52 - f2 ………….(1)
MEAN = Σfixi / Σfi
50 = (3480 + 30f1 + 70f2) /120
50 × 120 = (3480 + 30f1 + 70f2)
6000 = 3480 + 30f1 + 70f2
6000 - 3480 = 30f1 + 70f2
2520 = 30f1 + 70f2
30f1 + 70f2 = 2520
10 ( 3f1 + 7f2) = 2520
3f1 + 7f2 = 2520/10
3f1 + 7f2 = 252 ……………(2)
3(52 - f2) + 7f2 = 252
[From eq 1]
156 - 3f2 + 7f2 = 252
156 + 4f2 = 252
4f2 = 252 - 156
4f2 = 96
f2 = 96/4
f2 = 24
Putting this value of f2 in eq 1
f1 = 52 - f2
f1 = 52 - 24
f1 = 28
Hence, the value of f1 is 28 & f2 is 24 .
HOPE THIS ANSWER WILL HELP YOU….
Similar questions :
The percentage of marks obtained by students of a class in mathematics are:
64, 36, 47, 23, 0, 19, 81, 93, 72, 35, 3, 1
Find their mean.
https://brainly.in/question/15913253
Find the mean of the following data is 20.6. Find the value of p.
https://brainly.in/question/15913405
Step-by-step explanation:
here is your answer
X=28 and y=24
