Problem 46E

Construct a 95% confidence interval for (p1 - p2) in each of the following situations:

a. n1 = 400, p̂1 = .65; n2 = 400, p̂2 = .58

b. n1 = 180, p̂1 = .31; n2 = 250, p̂2 = .25

c. n1 = 100, p̂1 = .46; n2 = 120, p̂2 = .61

Chapter 8: bivariate correlational research - When you see two things that are related, and you think are related, but actually have nothing to do with one another To be causal - Covariance - Internal validity - Temporal precedence Correlational strength - As you get a measurement change by this much on this chart or whatever - You get the same ratio change on the other chart for the other variable - This means that they are changing at the same rate o Either moving at the same amount in the same direction [perfect correlation o Or moving at the same amount in the opposite direction [perfect correlation - When they don’t move at the same rate; imperfect correlation – this is what r