which sample is used for a z-test and which test would use variance? what is the test to use when both variance is same what test would you use if a sample of variance in one sample is equal to that of a t t what is used in the sample z test what type of variance is used to check for finite how to choose between sample t and z in two sample what is the sample variance what test to use with two samples which test would you use for if what test would we use if what test to use to determine whether variance is known or unknown in two sample cases? if both populations variance is unknown which test is used? what is the difference between z and t what test is used for a finite variance test? what is the difference between z and t in two samples what test to use for finite variance what is the difference between a z and t what sample would a t test be used in what type of test for the variance in z is variance known or unknown