Question

Find the mean for the following data using step deviation method.

• A. $4$
• B. $5$
• C. $6$
• D. $7$

Answer 1

The correct option is C $6$

Answer:- By shortcut Method

Class interval width (w) = 2

$X_i$	$F_i$	$d=\frac{X-A}{i}$	$F_i{d}_i$
2	10	-1	-10
4=A	20	0	0
6	30	1	30
8	40	2	80
	$\Sigma f=100$		$\Sigma fd=100$

Mean = $A+\frac{\Sigma fd}{\Sigma f}\times w=4+\frac{100}{100}\times 2=4+2=6$

C)6