## 23.11 Quick review questions

1. True or false: For paired data, the mean of the differences is treated like the mean of a single variable.
2. True or false: The appropriate graph for displaying paired data is often a histogram of the differences.
3. True or false: The population mean difference is denoted by $$\mu_d$$.
4. True or false: The standard error of the sample mean difference is denoted by $$s_d$$.