When would you use a tstatistic vs a zstatistic A when the s

When would you use a t-statistic vs. a z-statistic?

A.

when the standard deviation is known and the sample population is normally distributed

B.

when the sample population is normally distributed

C.

Both a & b

D.

None of the above

Solution

D. None of the above.

T score is used when the standard deviation is unknown.