Question

Describe the conditions necessary for the variance to
have the value zero

Answer 1

If all the given variables are equal it means they dont vary and thus the resultant variance is zero.

Answer 2

variance to be zero: only one condition that ll the values or measurements of variable must be same.

variance = summation of (x - a)²
where is x is each data value in the collection
a is average of all data in the collection.
Summation of squares is zero implies that each square is zero.
each x -a must be 0.