Pls Solve this question step by step with the formula of :
Mean = (sigma fixi)/(sigma fi)
Attachments:
Answers
Answered by
1
we know that class mark(xi)= lower limit+upper limite of class/2. so the class marks is 12,14,16,18,20,22 and 28.
fi= 3,6,9,13,f,5 and 4.
fixi = 36,84,144,234,20f,110 and 96.
sigma fixi = 704+20f.
sigma fi = 40+f.
mean = sigma fixi/sigma fi
mean = 18 (given)
18 = 704+20f/40+f
704+20f = 18(40+f)
704+20f = 720+18f
20f-18f = 720-704
2f = 16
f = 8 hence f = 8.
fi= 3,6,9,13,f,5 and 4.
fixi = 36,84,144,234,20f,110 and 96.
sigma fixi = 704+20f.
sigma fi = 40+f.
mean = sigma fixi/sigma fi
mean = 18 (given)
18 = 704+20f/40+f
704+20f = 18(40+f)
704+20f = 720+18f
20f-18f = 720-704
2f = 16
f = 8 hence f = 8.
Similar questions