2. Which of the following statements is true? (A) A parameter is a number that describes some characteristic of a sample.
(B) An unbiased estimator is any statistic that is taken from a sample chosen by
random methods.
(C) A sampling distribution is the distribution of a statistic calculated from all possible
samples of the same size from the same population.
(D) The variability of a population distribution will decrease as the sample size
increases.
(E) A normal approximation can always be used for the sampling distribution of pas
long as the sample size is greater than 30.