A version of cluster sampling in which the elements are formed into clusters on the basis of their ...

A version of cluster sampling in which the elements are formed into clusters on the basis of their geographic proximity is _____ sampling.
 a. stratified simple random
  b. random
  c. judgment
  d. area

Q. 2

The standard deviation is expressed in terms of the original units of measurement but the variance is not.
  Indicate whether the statement is true or false

Q. 3

Cluster sampling is _____.
 a. a nonprobability sampling method
  b. the same as convenience sampling
  c. a probability sampling method
  d. None of the answers is correct.

Q. 4

The difference between the largest and smallest observations in an ordered data set is called the range.
  Indicate whether the statement is true or false