Which of the following is not a measure of dispersion?

**A. ** Range

**B. ** Standard deviation

**C. ** Arithmetic mean

**D. ** Variance

**Answer : ****Option C**

**Explaination / Solution: **

No Explaination.

No Explaination.

Workspace

Report

The range of the data 8, 8, 8, 8, 8 . . . 8 is

**A. ** 0

**B. ** 1

**C. ** 8

**D. ** 3

**Answer : ****Option A**

**Explaination / Solution: **

Range = L - S = 8 - 8 = 0

Range = L - S = 8 - 8 = 0

Workspace

Report

The sum of all deviations of the data from its mean is

**A. ** always positive

**B. ** always negative

**C. ** zero

**D. ** non-zero integer

**Answer : ****Option C**

**Explaination / Solution: **

Workspace

Report

The mean of 100 observations is 40 and their standard deviation is 3. The sum of squares of all deviations is

**A. ** 40000

**B. ** 160900

**C. ** 160000

**D. ** 30000

**Answer : ****Option B**

**Explaination / Solution: **

Workspace

Report

Variance of first 20 natural numbers is

**A. ** 32.25

**B. ** 44.25

**C. ** 33.25

**D. ** 30

**Answer : ****Option C**

**Explaination / Solution: **

Workspace

Report

The standard deviation of a data is 3. If each value is multiplied by 5 then the new variance is

**A. ** 3

**B. ** 15

**C. ** 5

**D. ** 225

**Answer : ****Option D**

**Explaination / Solution: **

Workspace

Report

If the standard deviation
of *x, y, z* is *p* then the standard deviation of 3*x* + 5 , 3*y*
+ 5 , 3*z* + 5 is

**A. ** 3*p* + 5

**B. ** 3*p*

**C. ** *p* + 5

**D. ** 9*p* + 15

**Answer : ****Option B**

**Explaination / Solution: **

Workspace

Report

If the mean and coefficient of variation of a data are 4 and 87.5% then the standard deviation is

**A. ** 3.5

**B. ** 3

**C. ** 4.5

**D. ** 2.5

**Answer : ****Option A**

**Explaination / Solution: **

Workspace

Report

Which of the following is incorrect?

**A. ** *P* (*A*) > 1

**B. ** 0 ≤ *P* (*A*) ≤ 1

**C. ** *P*(ɸ) = 0

**D. ** *P* (*A*) + *P* ()
= 1

**Answer : ****Option A**

**Explaination / Solution: **

No Explaination.

No Explaination.

Workspace

Report

The probability a red
marble selected at random from a jar containing *p* red, *q* blue and
r green marbles is

**A. **

**B. **

**C. **

**D. **

**Answer : ****Option B**

**Explaination / Solution: **

Workspace

Report