Discussion Forum



1)

 The mean deviation about  the mean for the following data is,

482021301_m1.PNG


A) 6.3

B) 1.5

C) 2.83

D) 1.733

Answer:

Option D

Explanation:

We have , the following data

482021390_m5.PNG

 Here , mean

$(\overline{x})=\frac{\sum x_{i}f_{i}}{\sum f_{i}}=\frac{4+16+50+56+54}{2+4+10+8+6}=\frac{180}{30}=6$

$\therefore$   Mean deviation about mean =$\frac{\sum f_{i}|x_{i}-\overline{x}|}{\sum f_{i}}$

=$\frac{2.(4)+4.(2)+10.(1)+8.(1)+6.(3)}{30}$

 = $\frac{8+8+10+8+18}{30}=\frac{52}{30}$≈ $\frac{17.33}{10}=1.733$