1st Year Statistics Chapter 4 TestMeasure of Dispersion

Q1. Multiple choice questions (Attempt all · 10 × 1 = 10)

1. Range can be calculated in open-end classes:

   1. Never

   2. Always

   3. Often

   4. Seldom

2. The distribution is positively skewed if:

   1. Mean < Mode

   2. Mean > Mode

   3. Mean > Median

   4. Both (b) and (c)

3. The variance expresses the variability of data in ______ as unit of data.

   1. Square of unit

   2. Square root of unit

   3. Same unit

   4. All of these

4. If X and Y are independent, then s.d. (X - Y) is equal to:

   1. 

   2. 

   3. S.D. (X) + S.D. (Y)

   4. S.D. (X) - S.D. (Y)

5. The mean deviation is least if deviations are taken from:

   1. Median

   2. A.M.

   3. Mode

   4. G.M.

6. A disadvantage of range is that it is based on:

   1. Absolute deviation

   2. Square deviation

   3. Two extreme observation

   4. Upper and quartile

7. For moderately skewed distributions, approximately 68% of the cases are included between:

   1. 

   2. 

   3. 

   4. None of these

8. Var (bX) = _______

   1. b Var(X)

   2. b² Var(X)

   3. Var(X)

   4. Var(X)b²

9. Which of the following statements is correct?

   1. Every symmetrical curve is mesokurtic

   2. Standard deviation is the mean squared deviations from the mean

   3. The standard deviatoin of a constant is constant

   4. The second moment about zero equals variance

10. If X and Y are independent, then Var(X - Y) is equal to:

    1. Var (X) + Var (Y)

    2. Var (X) - Var (Y)

    3. Var (X + Y)

    4. Zero