A researcher is studying the effect of a stress-reduction program on people's levels of cortisol (a stress hormone). She tests the cortisol levels of 50 people before starting the program, and then tests the participants' cortisol levels again after completing the program. She wants to test the claim that the stress-reduction program reduces cortisol levels. Which of the following describes the researcher's null and alternative hypotheses?
1. null hypothesis: 1 - 4 = 0; alternative hypothesis: 1-4 <0
2. null hypothesis: 1 - 4 <0; alternative hypothesis: 43-44 > 0
3. null hypothesis: Up = 0; alternative hypothesis: 4p <0
4. null hypothesis: 4p <0; alternative hypothesis: Wp = 0