Mean Deviation

Q.

Given n observations x₁, x₂ ......x_n and their central tendency a. Find the mean deviation about a.

1. M.D(a) = $\frac{\sum _{i=1}^n|x_i-a|}{n}$

2. M.D(a) = $\frac{\sum _{i=1}^n{x}_i-a}{n}$

3. M.D(a) = $\sum _{i=1}^n{x}_i-a$

4. a and b

Q.

The mean deviation from the mean for the set of observations – 1, 0, 4 is

1. less than 3

2. less than 1

3. greater than 4.9

4. greater than 2.5

Q. If the sum of the deviations of $50$ observations from $30$ is $50$, then the mean of these observations is:

1. $50$
2. $51$
3. $30$
4. $31$

Q. Arrange the following given equation in descending order of their positive roots

Q. For any two real numbers $x\&y,$ the inequality that holds true is

1. $|x+y|\le |x|-|y|$
2. $|x+y|\le |x|+|y|$
3. $|x+y|\ge |x|+|y|$

Q.

If $\mu$ is the mean of a distribution, then $\sum f_i(y_i-\mu )$ is equal to

1. mean deviation

2. standard deviation

3. 0

4. None of these