The elements of dynamic sequence are (). A. variable and degree B. time and index value C. time and degree D. primary and secondary and object

The elements of dynamic sequence are (). A. variable and degree B. time and index value C. time and degree D. primary and secondary and object

B
Dynamic sequence, also known as time sequence, consists of two basic elements: one is the time of data; the other is the statistical index value of time, which is traditionally called the development level of dynamic sequence

If the standard deviation of two variables is equal, it indicates the equality of two variables

Equal variance

For continuous variable sequence, if the first group is below 500 and the group median of adjacent groups is 550, then the group median of the first group is 550

The first group is below 500, which means that 500 belongs to the minimum value of the adjacent group. So the variable is 2 * (550-500) = 100, so the median value of the first group is 550-100 = 450

Can the arithmetic mean, median and mode of any variable sequence be calculated and used to measure the concentration trend of variables
It's better to give an example

Yes
Such as 1 1 2 5 3 4
Average = (1 + 1 + 1 + 2 + + 5 + 2 + 3 + 3 + 4) / 9=
Median = the fifth digit of the sequence from small to large = 2
Mode = the most frequent book = 1