A random sample of size 10 was taken from a population. The sample has a variance of zero. Which of the following statements must be true? I. The population also has a variance of zero.II. The sample mean is equal to the sample median.III. The ten data points in the sample are equal in numerical value.
A、 I only;
B、II only;
C、 III only ;
D、II and III
发布时间：2025-07-23 06:38:59
