The Arithmetic mean of the following series is 18 find out the missing frequency
Answers
The missing frequency f is 8
Step-by-step explanation:
Given the mean of the data is 18
(CI) Midvalue X d=X-A F f{d}'
11-13 12 -6 3 -3 -9
13-15 14 -4 6 -2 -12
15-17 16 -2 9 -1 -9
17-19 18 (=A) 0 13 0 0
19-21 20 2 F 1 F
21-23 22 4 5 2 10
23-25 24 6 4 3 12
........................................................................................................................
We know step Deviation method,
Mean
Where A= Assumed Mean,
h= Class size . here h= upperlimit - lowe limit=2
Mean
The missing frequency f is 8
Step-by-step explanation:
Given the mean of the data is 18
(CI) Midvalue X d=X-A F f{d}'
11-13 12 -6 3 -3 -9
13-15 14 -4 6 -2 -12
15-17 16 -2 9 -1 -9
17-19 18 (=A) 0 13 0 0
19-21 20 2 F 1 F
21-23 22 4 5 2 10
23-25 24 6 4 3 12
........................................................................................................................
We know step Deviation method,
Mean
Where A= Assumed Mean,
h= Class size . here h= upperlimit - lowe limit=2
Mean
Mean = 18+\dfrac{-8+F}{40+F} \times 2
\Rightarrow 18=18+\dfrac{-8+F}{40+F} \times 2\
\Rightarrow 18-18=\dfrac{-8+F}{40+F} \times2
\Rightarrow \dfrac{-8+F}{40+F} \times2=0
\Rightarrow \dfrac{-16+2F}{40+F} =0
\Rightarrow -16+2F=0
\Rightarrow 2F= 16
F=8
Missing frequency F is 8
Missing frequency F is 8