### CFA Practice Question

There are 434 practice questions for this study session.

### CFA Practice Question

Which statement(s) regarding the selection of an appropriate sample size is (are) false?

I. If the population is normally distributed and the population variance is known, use a t-score irrespective of sample size.
II. If the population is normally distributed and the population variance is unknown, use a z-score irrespective of sample size.
III. If the population is not normally distributed and the population variance is known, use a F-score only if n >= 30; otherwise it cannot be done.
IV. If the population is not normally distributed and the population variance is unknown, use a X2-score only if n >= 30; otherwise it cannot be done.
A. I and II
B. II, III and IV
C. I, II, III and IV
Explanation: All these statements are false. The correct statements would have been:
• If the population is normally distributed and the population variance is known, use a z-score irrespective of sample size.
• If the population is normally distributed and the population variance is unknown, use a t-score irrespective of sample size.
• If the population is not normally distributed and the population variance is known, use a z-score only if n >= 30; otherwise it cannot be done.
• If the population is not normally distributed and the population variance is unknown, use a t-score only if n >= 30; otherwise it cannot be done.