Question

Estimate the mean discount for the following data given below using step deviation method.

• A. $80$
• B. $81$
• C. $82$
• D. $83$

Answer 1

The correct option is A $80$

Answer:- Using Shortcut Method

Class interval width (i) = $100-90=10$

Percentage	Discount (F)	$d=\frac{X-A}{i}$	Fd
100	5	2	10
90	10	1	10
80 = A	15	0	0
70	20	-1	-20
	$\Sigma F=50$		$\Sigma Fd=0$

Mean ( By step deviation formula) = $A+\frac{\Sigma Fd}{\Sigma F}\times i=80+(\frac{0}{50}\times 10)=80+0=80$

A) Mean = $80$