# Statistical Sampling Question

When sampling from a non normal distribution with a known variance, which statistics should be used if the sample size is small and if sample size is large?

a. Large Sample = z-Statistic | small Sample = not available
b. Large sample = z-Statistic | Small Sample = Z-statistics
c. Large sample = t-Statistic | small sample = not available
d. Large sample = z-Statistic | small sample = t-Statistic

can anyone explain the answer of this question and if this kind of questions can come in exam.
i found this one from mock test from my institute.
Thanks.

### Is the answer d?

Is the answer d?
Saw it on Yahoo Answers
However Im not able to explain and I personally feel a surface knowledge of these topics would be enough.Expecting experts to comment..

You can remember this easily for the exam.
t comes earlier than z
So t for smaller samples and z for larger samples

### right answer is A- Large

right answer is A- Large Sample=Z-statistic | small sample= not available

i was hoping somebody will say this is irrelevant to PMP exam.Now i have to memorize this as well.