Question

1a.) Stratified Random Sampling involves:

a. Dividing the population into overlapping groups

b. Taking a random sampling of a percentage of the pre-chosen groups (usually 10% of total groups)

c. Choosing non-overlapping clusters (i.e. streets of a city) and collecting data from all members of the selected cluster

d. None of the above

1b.) A data set consists of the values 2, 6, 3, and 1. If we consider this a population (all the values available), the variance is

a. 12

b. 14

c. the square root of 3.5

d. the square root of 14

e. none of the above

1c.) Range of a large set of data is 12. Variance is about

a. 12

b. 3

c. the square root of 12

d. none of the above

Answer 1

1. Stratified random sampling involves dividing the population into smaller groups on the basis of some characteristic and are non-overlapping with each other.
Correct option: C)

2.

X	(X - 3)^2
2	1
6	9
3	0
1	4
Average = 3	Sum = 14

Variance = 14/n = 14/4 = 3.5

Correct option: E) None of the above

3. Range is the difference between the maximum and minimum values while variance is the average squared deviation from the mean. Hence, there is no relation between the both.
Correct option: None of the above