23.3 Mean differences: Notation
The notation used for paired data reflects how we work with the differences (Table 23.1). Apart from that, the notation is similar to that used in Chap. 22.
| One sample mean | Mean of paired data | |
|---|---|---|
| The observations: | Values: \(x\) | Differences: \(d\) |
| Sample mean: | \(\bar{x}\) | \(\bar{d}\) |
| Standard deviation: | \(s\) | \(s_d\) |
| Standard error of sample mean: | \(\displaystyle\text{s.e.}(\bar{x}) = \frac{s}{\sqrt{n}}\) | \(\displaystyle\text{s.e.}(\bar{d}) = \frac{s_d}{\sqrt{n}}\) |
| Sample size: | Number of observations: \(n\) | Number of differences: \(n\) |