Computing a two-independent sample t-test is appropriate when?
A) different participants are assigned to each group
B) the population variance is unknown
C) participants are observed one time
D) all of the above
To compute a related samples t-test, a researcher has to know many values. Which of the following is NOT a value that the researcher must know to compute this test?
A) the estimated standard error for difference scores
B) the population variance of difference scores
C) the sample size or number of pairs of scores
D) the sample variance of difference scores