Question

Calculate the approximate mean number of shops inside the market using step deviation method.

• A. $75$
• B. $74$
• C. $71$
• D. $77$

Answer 1

The correct option is D $77$

Answer:-

Class interval width (i) = 10

Market X	Shops F	$u=\frac{X-A}{i}$	Fu
55	1	-1	-1
65 = A	4	0	0
75	7	1	7
85	10	2	20
	$\Sigma f=22$		$\Sigma fu=26$

By using step deviation method

Mean = $A+\frac{\Sigma fu}{\Sigma f}=65+\frac{26}{22}\times 10=65+11.81=76.81\simeq 77$

D) 77