8.1 Introduction

Two independent sample \(t\)-tests are used to compare the means of two separate groups.

Consider the face-plant data (Wojcik et al. 1999) used in the textbook (Table 8.1).

TABLE 8.1: Lean-forward angles for older and younger women
Younger women
Older women
29 34 18
32 27 15
34 32 23
31 28 13
33 27 12

The data file (forwardfall.sav) can be downloaded in Sect. 10.

You can download the data, and follow the instructions.

References

Wojcik, Laura A., Darryl G. Thelen, Albert B. Schultz, James A. Ashton-Miller, and Neil B. Alexander. 1999. “Age and Gender Differences in Single-Step Recovery from a Forward Fall.” Journal of Gerentology 54A (1): M44–50.