1. Hypothesis testing –Revisited A method for deciding whether the sample that you are looking at has been changed by some type of treatment (Independent Variable IV) Looking at how likely it is that a sample like the one that you have would be selected at random (without the benefit of treatment).

2. Sampling Distribution Mean values of all possible samples. Frequency How many samples  xx

3. Sample means 81 85 Z scores -2.56 0 H1H1 H1H1 p =.0052.0052 <.025

4. Sample means 81 85 Z scores -2.56 0 H1H1 H1H1 Z = -1.96-2.56 is more extreme than -1.96

5. Sample means 50 52 Z scores 0 1.58 H1H1 H1H1 p =.0571.0571 >.025

6. Sample means 50 52 Z scores 0 1.58 H1H1 H1H1 1.58 is less extreme than 1.96 Z = 1.96