Briefly explain what the 95 interval estimate tells you.
Question 2
Which of the following statements are true?
a. The pooled-variances t-test is used whenever the population standard deviations are assumed to be equal regardless of the sample size.
b. The unequal-variances t-test is used whenever the population standard deviations are unknown and cannot be assumed to be equal.
c. The z-test can be used as a close approximation to the unequal-variances t-test when the population standard deviations are not assumed to be equal, but samples are large (each n 30).
d. All of these statements are true.
e. None of these statements is true.