In testing the difference between two population means for which the population variances are unknown and not assumed to be equal, two independent samples are drawn from the populations. Which of the following tests is appropriate?
a. z-test c. unequal variances t-test
b. pooled-variances t-test d. None of these choices.
Question 2
We calculate the three-period moving average for a time series for all time periods except the first period.
Indicate whether the statement is true or false