If the standard deviation of a set of data is zero, what can you conclude about the set of values?

Step-by-step explanation:

I think it means every data value should be equal to the "mean" to make the standard variation of this set to be zero. Or all data value of the set are equal.

true statements:

a) x + y = y + x   ⇒ commutative property of addition

b) (x * y) * z = x * (y * z) ⇒ associative property of multiplication

d) (x + y) + z = x + (y + z) ⇒ associative property of addition

false statements:

c) x - y = y - x   should be: x - y = - y + x

e) (x - y) - z = x - (y - z) should be: (x - y) - z = x - (y + z)

step-by-step explanation:

what