D.18 Answers: Sampling variation
Answers to exercises in Sect. 18.8
Answer to Exercise 18.1:
1. Standard deviation.
2. Standard error. More specifically, the standard error of the mean.
3. Standard deviation.
4. Standard error. More specifically, the standard error of the proportion.
Answer to Exercise 18.2:
1. No: Population proportions don’t vary from sample to sample.
2. Yes: varies from sample to sample.
3. Yes: varies from sample to sample.
4. Yes: varies from sample to sample.
5. No: Population odds don’t vary from sample to sample.
Answer to Exercise 18.3:
The standard error of the mean is used to
describe how much the sample mean is likely to vary from sample to sample.
Alternatively,
it describes how precisely the sample mean is estimating the (unknown) population mean.