Browse Questions

# Find the mean deviation about the mean for data :

$\begin{array}{1 1}(A)\;15.92\\(B)\;11.288\\(C)\;2.34\\(D)\;7.56\end{array}$

Step 2:
Mean $\bar {x} = A +\large\frac{\sum f_id_i}{\sum f_i }$$\times h \qquad= 130+ \large\frac{(-47)}{100}$$ \times 10$
$\qquad = 130- 4.7$
$\qquad= 125.3$
Mean deviation about the mean $= \large\frac{\sum f_i |x_i -\bar{x}|}{\sum f_i}$
$\qquad= \large\frac{1128.8}{100}$
$\qquad= 11.2888$
Hence B is the correct answer.