Question

Assertion : The mean deviation of the data $2,9,9,3,6,9, 4$ from the mean is $2.57$
Reason : For individual observation, Mean deviation $(\overline{ X })=\frac{\sum\left|x_{i}-\bar{x}\right|}{n}$

• A. Assertion is correct, reason is correct; reason is a correct explanation for assertion.
• B. Assertion is correct, reason is correct; reason is not a correct explanation for assertion
• C. Assertion is correct, reason is incorrect
• D. Assertion is incorrect, reason is correct.

Answer 1

Answer: (A)

Mean $(\overline{ X })=\frac{2+9+9+3+6+9+4}{7}$
$=\frac{42}{7}=6$
$MD(\overline{ X })=\frac{\sum\left|x_{i}-\bar{x}\right|}{n}$
$=\frac{4+3+3+3+0+3+2}{7}=\frac{18}{7}$
$=2.57$